How do these forces affect the car's
movement?

Answer:

I rephrased your question:

Two objects with equal masses are in motion. which object will have more kinetic energy?

A) the object with the greater speed

B) the object with the greater density  

C) the object with the greater acceleration

D) the object with the greater acceleration

E) the object with the greater volume

F) the object with the greater volume

Explanation:

Kinetic Energy is equal to (1/2)mv^2, where m is the mass and v is the velocity.

-----

A) the object with the greater speed   YES

B) the object with the greater density  NO

C) the object with the greater density  NO

D) the object with the greater acceleration MAYBE.  Acceleration means energy is being added, so it depends on how much and the masses of each object.

E) the object with the greater volume  NO

Answer:

Explanation: Two objects with equal masses are in motion. Which object will have more kinetic energy?

Responses

the object with the greater density

the object with the greater volume

the object with the greater acceleration

the object with the greater speed

Answer: The object with the greater speed

a) The normal force on the block of mass M is 76.383 N in magnitude.

b) The hanging block goes upward in one direction.

c) The block's acceleration has a common magnitude of 8.11 m/s2.

d) The string's tension measurement is 161.19 N in magnitude.

e) After 2.0 seconds, the speed of the hanging mass is 5.695 seconds.

Simply put, "distance or quantity" is the definition of size. In terms of motion, it shows the absolute or relative size, direction, or movement of an object. It is used to describe something's size or scope. Magnitude in physics typically refers to size or quantity.

It's given that:

M = 45.2 kg.

µk = 0.10.

m = 9.0 kg.

angle = 30 degree

A) The block's mass M and the normal force's strength N:

N - mgcosθ = 0

= 9 * 9.8cos 30

= 76.383N

B) The hanging block's direction shifts upward.

C) the typical magnitude of the acceleration of the block is

Mg - T = Ma

(Mg - T) / M = a

(45.2 * 9.8 - 76.383) / 45.2 = a

[tex]8.11\frac{m}{s^{2} } = a[/tex]

D) the string's tension, T, in terms of magnitude

T - mg = ma

T = ma + mg

T = 9 * 8.11 + 9 * 9.81

T = 161.19N

E) the dangling mass's speed after a delay of 2.0 seconds

v² - u² = 2as

v² - 0² = 2as

v² = 2as

v = √2as

v = √2*8.11*2

v = 5.695 m/s

COMPLETE QUESTION: Two blocks are connected by a light but sturdy string wrapped around a mass-less pulley. The rough inclined surface makes an angle of 30 degrees with the horizontal. The block on the inclined surface has a mass M = 45.2 kg. Assume the coefficient of kinetic friction between the union of mass M and the inclined plane is µk = 0.10. The vertically hanging block has mass m = 9.0 kg. Assume the blocks begin their motion from rest.

(a) (10 points) What is the magnitude N of the normal force on the block of mass M?

(b) (5 points) In What direction does the hanging block m move, up or down? Circle one.

(c) (18 points) What is the common magnitude of the acceleration of the blocks?

(d) (14 points) What is the magnitude T of the tension in the string?

(e) (6 points) What is the speed of the hanging mass after a time period of 2.0 seconds?

To know more about the magnitude, refer to this link:

https://brainly.com/question/2596740

#SPJ4

The water molecules in the gas phase have more kinetic energy than in the liquid phase. The molecules in the liquid phase must absorb energy from the surroundings to enter the gas phase.

A hot spring can be defined as a natural or an artificially-induced phenomena in which very hot groundwater flows out from the Earth's crust due to the heat energy that is present in the geosphere.  

A phase change simply refers to the change in the state (phase) of matter of a given chemical compound or substance in the following ways:

Generally speaking, the water molecules in the gas phase typically possesses more kinetic energy than in the liquid phase and as such, it would have to absorb more energy from the surroundings in order to enter the gas phase.

Read more on hot springs here: brainly.com/question/4421633

#SPJ1

Voltage produced in the secondary voltage is 1,600 V

A current transformer (C.T.) is a type of "transducer" that produces an alternating current in a secondary winding that is proportional to the current sensed in the primary winding. Current transformers reduce high voltage currents to much lower values ​​and provide a convenient way to safely monitor the actual current flowing in AC transmission lines using a standard ammeter. The working principle of a simple current transformer is slightly different from that of a normal voltage transformer. To calculate voltage in the secondary coil:

N₁/N₂ = V₁/V₂

where;

N₁ is number of turns in primary coil

N₂ is number of turns in secondary coil

V₁ is voltage in primary coil

V₂ is voltage in secondary coil

Now for the given case,

150/2000 = 120/V₂

V₂ = (120 x 2000)/150

V₂ = 1,600 V

To know more about current transformer visit:

https://brainly.com/question/7551270

#SPJ4

The recoil speed of the gun is 6.39m/s

What is recoil speed of the gun ?
After firing the bullet, the bullet moves forward with a large momentum and the gun moves backward with an equal momentum. Let m and M be the masses of bullet and gun, respectively. If v and V are the velocities of the bullet and gun, respectively after the firing then:-

0= mv+ MV

Therefore V=-mv/M

The negative sign indicates that the gun moves in a direction to that of
the bullet.
m1v1 = m2v2

m1 = mass of bullet

v1 = velocity of bullet

m2 = mass of gun

v2 = velocity of gun

m1v1=m2v2

0.25*230=9*v2

v2=0.25*230/9 = 6.39m/s

The recoil speed of the gun is 6.39m/s
To know about recoil speed  from given link
https://brainly.com/question/15435914
#SPJ9

If we are to write 3500 in units with the appropriate prefixes, this would be 3.5kg.

This refers to the metric system that is used and accepted internationally and is used as a standard for the measurement of items

Hence, when it comes to the use of SI Units, the name of the unit with the prefixes deka, hecto, and kilo are used, meaning, respectively, 10, 100, and 1000.

With this in mind, 1000 units would make one kilo and if we are to write this mathematically this would be 3500 divided by 1000 which is 3500/100, and which would be 3,5.

Therefore, the correct answer is 3.5kg.

Read more about SI Units here:

https://brainly.com/question/15657466

#SPJ1

Answer:

3*10^3 g or 0.3*10^4 g

Explanation:

The average fluid velocity (in m/s) is 3.636 m/s.

The volume of fluid moving past a spot in a given amount of time is measured as the flow rate. Circular and noncircular pipelines both experience fluid flow in daily life.

From the question we have given:

The diameter of the pipe (l) is  3.00 cm or 0.0300 m.

The magnetic field (B) is  0.550 T.

The hall voltage (E) is  60.0 mv or 60 x 10⁻³ v.

  [tex]v = \frac{E}{Bl}[/tex]

The average fluid velocity can be calculated using the equation E = Blv.

In this instance, the width really corresponds to the diameter:

[tex]v = \frac{60 \;*\; 10^{-3} \;V}{0.0165\; m} \\[/tex]

[tex]v = 3.636 \;m/s[/tex]

Thus, the average fluid velocity is 3.636 m/s.

Visit the link below to learn more about the average fluid velocity:

brainly.com/question/19130911

#SPJ4

Given:

The length of the pipe is L.

The third harmonic has teh wavelength,

To find:

The type of the pipe

Explanation:

The wavelength of the harmonics for a pipe closed at one end is,

The wavelength of the harmonics for a pipe open at both the ends is,

Here,

The given wavelength is,

which resembles the form,

Hence, the pipe is open at the other end.

a) Yes, provided that the speed is parallel to the magnetic field.

b) No, it is not possible electric field to be zero.

c) No. the magnetic force can be zero.

Magnets, which can be used to repel or attract other things, exert a force known as magnetism. One of the fundamental forces of nature, electromagnetic, is one of the components of this potent physical phenomenon. A magnetic field is produced when electrically charged particles, which are present in all matter, move.

a)Yes, provided that the speed is parallel to the magnetic field.

b) No, the electric force acting on a charge travelling in an electric field cannot be zero since the electric field's amplitude and direction are independent of the motion or velocity of the charged particles.

c) No, the electric force cannot be zero because it is unaffected by the motion of the particles, but the magnetic force can be zero.

To know more about Magnetic force visit:

https://brainly.com/question/10353944

#SPJ4

Wake turbulence is near maximum behind a jet transport just after take off because of the high angle of attack and high gross weight.

Explanation:

Every aircraft generates wake turbulence while in flight. Wake turbulence is a function of an aircraft producing lift, resulting in the formation of two counter-rotating vortices trailing behind the aircraft.

Wake turbulence from the generating aircraft can affect encountering aircraft due to the strength, duration, and direction of the vortices. Wake turbulence can impose rolling moments exceeding the roll-control authority of encountering aircraft, causing possible injury to occupants and damage to aircraft. Pilots should always be aware of the possibility of a wake turbulence encounter when flying through the wake of another aircraft, and adjust the flight path accordingly.

Wake turbulence is near maximum behind a jet transport just after take off because of the high angle of attack and high gross weight.

To learn more:

https://brainly.com/question/4853035

If the two wires make the same angle with the vertical, the angle must be 83.6⁰.

The angle between the two wires is determined by applying the principle of parallelogram law of vector addition.

R² = a² + b² - 2abcosθ

where;

W² = (0.75W)² + (0.75W)² - 2(0.75W x 0.75W) cosθ

W² = 1.125W² - 1.125W² cosθ

W² = 1.125W²(1 - cosθ)

W²/1.125W² = 1 - cosθ

0.8889 = 1 - cosθ

cosθ = 1 - 0.8889

cos θ = 0.1111

θ = arc cos(0.1111)

θ = 83.6⁰

Thus, the angle between the two wires is determined as  83.6⁰.

Learn more about resultant vector here: https://brainly.com/question/110151

#SPJ1

The force needed to be applied by each person is 5.150×10^3 N.

The required acceleration is 3.4 m/s2 and the mass of the car is 2,159 kg.

According to Newton's second law:

F = ma

F =  2,159 × 3.4.

F = 7340.6 N

Adding the force of friction into it

F = 7340 + 310

F = 7650.6 N

Since two people need to apply the force

F = 7650 N / 2

F = 3,825.3 N

or

F = 3.825×10^3 N

The force applied by each person to push the car is 3.825×10^3 N.

If you need to learn more about force related questions, click here

https://brainly.in/question/47823592?referrer=searchResults

#SPJ4

At an amusement park there is a ride in which cylindrically shaped chambers spin around a central axis and the radius of a chamber            r= 0.387 m

Given

  Mass of the person m = 70.2 kg

  speed v = 3.09 m/s

  Force F = 560N

-------------------------------------------

  We have the formula for the force is given by

           F = ( mv2) /r

 The radius of the chamber is given b y

          r = ( mv2) /F

           =  ( ( 70.2 kg)(3.09 m/)2) /(560N)

         r=0.387 m

A circle's or a sphere's radius is the distance along a line connecting its centre and perimeter. From any point on the circle's or sphere's circumference to the centre, the radius' length is constant. Its length is halved by its diameter. The radius is a line segment connecting the centre of a circle or sphere to its perimeter or boundary in geometry.You'll require more effort as you reduce the radius because you're dividing by a lower force.

Learn more about radius here:

https://brainly.com/question/24051825

#SPJ4

Answer:

a - constant speed walking north (positive)

b,c,d - accelerating north (positive)

e - stopped

f - negative walking at a constant speed

Explanation:

When the line is straight with a constant slope the person is hiking at a constant speed. If the line curves they are accelerating if it is flat they are not moving and if it has a negative slope the hiker is moving south

While negative point charges always move in the direction of the opposing electric field, positive point charges always move in the other direction. An electric field is a vector quantity. They cannot be added directly, but they can be vectorially inserted.

A physical field called an electric field surrounds electrically charged particles and attracts or repels all other charged particles nearby. It can also refer to the physical field surrounding a system of charged particles.

While negative point charges always move in the direction of the opposing electric field, positive point charges always move in the other direction. An electric field is a vector quantity.

Learn more about Electric field here:

brainly.com/question/8971780

#SPJ1

We will have that the power will be:

So, the power was 220 Watts.

a)The total resistance of the rod R = 2.1 * 10^(3)Ω

b) current Density when voltage ΔV is applied between two ends is J(x) = [tex]=\frac{12\sigma_o\Delta V}{L}[/tex]

c) Steady-state electric field is E(x) = [tex]\frac{12\Delta V}{L^3} x^2\hat{i}[/tex]

a) Consider a small slice of the rod of thickness dx situated at a distance x from the center of the rod.

L = length of rod = 2cm, d= diameter = 0.5cm,  

Given [tex]\sigma(x)=\sigma_oL^2/x^2[/tex]     where σ is the rod's conductivity.

[tex]\sigma_o = 4 * 10^{-2}(\Omega.m)^{-1}[/tex]        (given)

The resistance dR of this small section of the rod is

dR=[tex]\frac{\rho_rdx}{A}=\frac{dx}{\sigma_rA} = \frac{4x^{2} dx}{\sigma_o L^2\pi d^2}[/tex]

The total resistance of the rod can be found by the integral of these smalls sections over the whole rod

[tex]R = \int\limits^{L/2}_{-L/2} \, dR = \int\limits^{L/2}_{-L/2} \,\frac{4x^2dx}{\sigma_oL^2\pi d^2}=\frac{4x^3}{3\sigma_oL^2\pi d^2} |_{-L/2}^{L/2} = \frac{L}{3\sigma_o\pi d^2}[/tex]

⇒R = (2*10^(-2)) / (3 * 4 * 10 ^(-2)* π * 0.5 * 10^(-2))

⇒R = 2.1 * 10^(3) Ω

Thus the total resistance of the rod R = 2.1 * 10^(3) Ω

b)The current density when voltage ΔV is applied between two ends is given by

J(x) [tex]=\frac{I}{A}=\frac{4\Delta V}{R\pi d^2} =\frac{12\sigma_o\Delta V}{L}[/tex]

c) the steady-state electric field is  

[tex]E(x) = \frac{J(x)}{\sigma} =\frac{12\sigma_o \Delta V / L}{\sigma_o L^2 / x^2} \hat{i} = \frac{12\Delta V}{L^3} x^2\hat{i}[/tex]

The question is incomplete. The full question is probably " A cylindrical glass rod is heated with a torch until it conducts enough current to cause a light bulb to glow. The rod has a length of L=2.0cm, and a diameter of d= 0.5cm, and its ends, plated with the material of infinite conductivity, are connected to the rest of the circuit. When red hot, the rod’s conductivity varies with position x measured from the center of the rod as [tex]\sigma(x)=\sigma_oL^2/x^2[/tex] with [tex]\sigma_o = 4 * 10^{-2}(\Omega.m)^{-1}[/tex]  a)What is the resistance of the glass rod?  Express your answer both symbolically and as a value in ohms. b)When a voltage ΔV is applied between the two ends, what is the current density J(x)?  c)What is the steady-state electric field E(x)? "

Problem on surface current density:

brainly.com/question/13958826

#SPJ4

The object took 15.3 seconds to reach the ground when released.Then the height of the object just prior to being released will be 1147 m.

Gravity, g of is a downward force acting on a body which is moving or at rest at positioned at a height h from the surface.

Gravity is the downward acceleration of a moving body and it have value equal to 9.8 m/s². If the time taken to hit the ground when released from a height is t, then thee equation connecting this time, height h and g is written as follows;

h = 1/2 gt².

Hence, the height of the object prior to the point of releasing is calculated as follows:

h = 1/2 9.8 m/s² × (15.3 s )²

  = 1147 m.

Therefore, height of the object just prior to being released will be 1147 m.

To find more about gravity, refer the link below:

https://brainly.com/question/4014727

#SPJ1

If the speed of the car is increased by 65%, the stopping distance of the car will be increased by 272.25%.

Let us say, the car is moving with velocity U, the stopping time of the car is T and the stopping distance of the block is d,

Now, we should use the equation of motion,

U²-V² =2aD

Where,

U is initial velocity,

V is final velocity,

D is the stopping distance,

a is the acceleration.

We know, at the final velocity will be zero,

So,

U² = 2aD

U =√(2aD)

Now, if the speed is increased by 65%, let us say the stopping distance becomes D'.

So,

U+65%U = √(2aD')

165U/100 = √(2aD')

Now, putting U = √(2aD),

165√(2aD)/100 = √(2aD')

(1.65)²D = D'

D' = 2.7225D

Now,

∆D = D' - D/D × 100

∆D = 2.7225 × 100

∆D = 272.25%

So, the stopping distance increased by 272.25%.

To know more about stopping distance, visit,

https://brainly.com/question/26711747

#SPJ4

The mass of the bob has no bearing on the pendulum's time period.The time duration would therefore remain the same if the mass of the bob doubled.

Solve the problem ?

      To learn more about pendulum refer

      https://brainly.com/question/26146375

       #SPJ4

The gauge pressure at the depth of 210 m will be 2.11974 x 10^{6} Pa .

What is gauge pressure ?

The amount of pressure measured in relation to the applied atmospheric pressure is known as gauge pressure. A diaphragm sensor can be used to measure gauge pressure, with one side of the diaphragm exposed to the pressure medium that has to be measured and the other exposed to the surrounding atmospheric pressure.

The pressure from the weight of the atmosphere is included in gauge pressure readings because gauge pressure is zero-referenced against ambient air (or atmospheric) pressure. This indicates that gauge pressure varies in response to both weather and height above sea level. Gauge pressure measurement is adequate for the majority of industrial applications because every operation in a refinery or manufacturing facility operates at the same air pressure.

The gauge pressure is ;

P = density x g x depth

where , density is of sea water .

Calculate the gauge pressure as -:

P = density x g x depth

  = (1030 kg/m^{3})(9.8 m/s^{2})(210 m)

  = 2.11974 x 10^{6} Pa .

To learn more about the gauge pressure from the link ;

https://brainly.in/question/28717015

#SPJ4

If a car can go from 0 - 69 mi/hr in 8.0 seconds, then the final speed after 5.0 seconds would be 41.6 m/s, if its starting speed was 50 mi/hr.

The total displacement covered by any object per unit of time is known as velocity. It depends on the magnitude as well as the direction of the moving object.

The acceleration of the car If a car can go from 0-69mi/hr in 8.0 seconds,

69 miles / hour = 69 × 1609 / 3600

                          = 30.83 m / s

v = u + at

30.83 = 0 + a × 8.0

a = 30.83 / 8.0

  = 3.85 meters / second²

50 miles per hour = 50 × 1609 / 3600

                              = 22.35 m / s

The velocity of the car after 5 seconds,

v = 22.35 + 3.85 × 5

  = 41.6 m / s

Thus, the velocity of the car after 5 seconds would be 41.6 m / s.

To learn more about Velocity here, refer to the link ;

brainly.com/question/18084516

#SPJ1

The conclusion reached by the student who is most warranted is that the comet originates between the Sun and the asteroid belt.

Can humans survive on an aster?

The magnetic field and atmosphere that protect humans on Earth from harm are absent on asteroids. One approach to shield yourself from dangerous radiation is to live inside an asteroid. It is expected that humans would be sufficiently protected from radiation by excavating 100 meters beneath an asteroid.

How likely is it that an asteroid will strike Earth?

While space rocks of this size are most likely to reach Earth only about once every hundred million years, NEOs that are 50 to 100 meters (164 to 328 feet) broad have the potential to strike much more frequently—roughly every thousand years.

To know more about Asteroid visit here:

brainly.com/question/2826424

#SPJ4

Comets orbit the Sun in incredibly eccentric paths. They move in close proximity to the Sun from the outer solar system to the inner solar system via their orbits. Comets may have carried water and other materials to Earth through crashes early in the planet's history.

As the comet approaches the Sun, the outer ice layers melt and create a luminous coma, which causes comet tails to develop. This gas and dust are pushed into a long tail by particles streaming from the Sun. Always facing away from the Sun is the tail. The coma appears vivid because it reflects sunlight . Comets only briefly appear when they are close to the Sun. As they move, they appear to vanish.

To know more about comets refer the link below

https://brainly.com/question/12443607

The correct answer is option C.

Two electromagnetic waves are traveling through a material. Wave 1 has a maximum electric field strength that is three times the maximum field strength of wave 2. The average intensity of Wave 1 is nine times the intensity of Wave 2.

By comparing the two electromagnetic waves, we get:

Maximum Electric Field Strength of Wave(1) = 3 x Maximum Electric Field Strength of Wave (2), i.e.

[tex]E_{1}[/tex]  = 3 x [tex]E_{2}[/tex]

Now comparing the average intensities of the two waves. we get [tex]\frac{I1}{I2}[/tex]

The average intensity of electromagnetic wave 1 can be expressed as:

[tex]I_{1}[/tex] = [tex]\frac{1}{2}[/tex] x ε0 x  [tex]E1^{2}[/tex] x c ------- (1)

Now, the average intensity of the electro-magnetic wave 2 can be expressed as:

[tex]I_{2}[/tex]  =  [tex]\frac{1}{2}[/tex] x ε0 x  [tex]E2^{2}[/tex]  x c -----(2)

Now comparing equations 1 and 2 we get.

[tex]\frac{I1}{I2}[/tex]  =   [tex]E1^{2}[/tex] /  [tex]E2^{2}[/tex]

[tex]\frac{I1}{I2}[/tex]  =  ( 3 x [tex]E2)^{2}[/tex]/  [tex]E2^{2}[/tex]

[tex]\frac{I1}{I2}[/tex]  = 9

Thus, we can say that the average intensity of Wave 1 is nine times the intensity of Wave 2.

If you need to learn more about electromagnetic waves click here:

https://brainly.com/question/3871471

#SPJ4

The complete question is:

Two electromagnetic waves are traveling through a material. Wave 1 has a maximum electric field strength that is three times the maximum field strength of Wave 2. How do the average intensities of the waves compare?

a. The average intensity of Wave 1 is three times the intensity of Wave 2.

b. The average intensity of Wave 2 is three times the intensity of Wave 1.

c. The average intensity of Wave 1 is nine times the intensity of Wave 2.

d. The average intensity of Wave 2 is nine times the intensity of Wave 1.

The bond angle of the molecule to the nearest degree is 120 degrees.

According to the valence shell electron pair repulsion theory (VSEPR). We know that the bond angle that an atom has with its neighbors which also call the dihedral angle of the compound is affected by the number of atoms that surround the central atom in the molecule.

Let us recall that when we have two atoms that surround the central atom then we are going to have a three atom compound which has a trigonal planar geometry and has a bond angle of 120 degrees.

Learn more about VSEPR theory:https://brainly.com/question/14992767

#SPJ1

Answer:

Explanation:

Given:

V₁ = 20 m/s

ΔS = 200 m

V₂ = 15 m/s

___________

S - ?

Car motion equation:

X₁ = V₁*t = 25*t

X₂ = ΔS  + V₂*t = 200 + 15*t

Since the second car overtook the first, then:

X₁ = X₂

25*t = 200 + 15*t

5*t = 200

t = 200 / 5 = 40 с

Distance:

S = ΔS + V₂*t = 200 + 15*40 = 200 + 600 = 800 m

Correct answer:

A) 800 m

Given Data:

The applied acceleration is constant.

speed of the car after time,t1 = 20s, is V1=  54 km/h = 15 m/s

speed of the car after time,t2 =  60s, is V2= 108 km/h = 30m/s

we use the formula, V = Vo + a x t

where, Vo is the initial speed, a is the acceleration(constant),

t is the time taken by the object.

a) Acceleration = rate of change of speed with time = V2 - V1 / t2 - t1

a = 30-15/60-20

a = 15/40 = 0.375 m/[tex]{s^{2} }[/tex]

b) Initial speed, Vo = V1 - a x t1

                                = 15 - 0.375 x 20

                                 = 7.5 m/s

c) Speed after 40 s, V = Vo + a x t, t = 40s

                                     = 7.5 + 0.375 x 40

                                      = 22.5 m/s

To know more about problems on mechanics, visit,

https://brainly.com/question/13488869

#mechanics

Answer:

20 N

Explanation:

logically it'd be 20 N due to the fact that it's a rectangular shape. You pretty much look at the counterpart and copy and paste it to the other side.

The distance between the points A and B is 6000 miles.

Let us assume that the distance between the points a and b is D.

Now, we know, airplane takes 4 hours and 48 minutes to move from a to b and back with no wind

Let us say the speed of the airplane is V.

So, we know,

Average Speed = total distance/total time

The distance between a to b and back is 2D.

So, we can write,

V = 2D/4.8

2D = V(4.8)

With wind of speed V'=100mph, it take 5 hours for the airplane to go from a to b ane back.

The average velocity of airplane in wind is,

V + V' = 2D/5

Putting value of 2D,

V + V' = V(4.8)/5

5(V + 100) = 4.8V

5V + 500 = 4.8V

0.2V = -500

V = -2500mph

The negative sign only means that we have taken the opposite direction, so that is not a problem and we can ignore it,

So,

We know,

2D =V(4.8)

D = 2500(4.8)/2

D = 6000 miles.

So, the distance between the two points is 6000 miles.

To know more about Velocity, visit,

https://brainly.com/question/80295

#SPJ4

a) The velocity of stone after 7 seconds is 1.62 m/sec.

b) The velocity of the stone after it has risen 25 m is  -[tex]\sqrt{17}[/tex]

a) h(t) = 10t - 0.83[tex]t^{2}[/tex]

   velocity = [tex]\frac{dh}{dt}[/tex](t) = 10 - 2*0.83*t

   [tex]\frac{dh}{dt}[/tex] (7) = 10 - 2*0.83*7

            = 1.62 m/sec

The stone after 7 seconds is 1.62 m/sec

b) h(t) = 25

    10t - 0.83[tex]t^{2}[/tex]  = 25

    t = 50/83 (10 + [tex]\sqrt{17}[/tex])

    [tex]\frac{dh}{dt}[/tex] = 10 - 2*0.83*(50/83)(10 + [tex]\sqrt{17}[/tex])

         = 10 - (10 + [tex]\sqrt{17}[/tex])

          = - [tex]\sqrt{17}[/tex] m/sec.

The stone after it has risen 25 m is  - [tex]\sqrt{17}[/tex] m/sec.

Learn more about Velocity here:

https://brainly.com/question/18084516

#SPJ4