A slide projector projects images on a screen. a) If the slide is 15.5 cm from the lens and the lens has a focal length of 15 cm, how far away is the screen

Answer:

Darkness takes up the space that light does not.

Answer:

The answer is temperature lol

Explanation:

:)

Answer:

one could freeze and the second would thaw

Explanation:

sorry if its wrong

The two examples of how land can have a dramatic change in temperature

is during freezing and thawing.

Cold temperatures which is common during the winter period is

characterized by the formation of snow and freezing of smaller water

bodies.

There may be a short phase in which there is relative sunlight which melts

the frozen substances thereby forming liquids . This is usually as result of

the temperature being on the increase in the atmosphere.

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Answer:

- 670 kg.m/s

Explanation:

Newton's third law states that to every action, there is equal and opposite reaction force. Since the force will be same but different in direction and acted in the same time then the impulses ( force multiply by time) of the two car be same in magnitude but different in direction - 670 kg.m/s

Answer:

6m/s

Explanation:

The tangential velocity is the product of the linear velocity and the radius. This is expressed as;

v = wr

w is the angular velocity = 3rad/s

r is the radius = 2m

Substitute

v = 3 * 2

v = 6m/s

Hence the tangential velocity of the object is 6m/s

Answer: 85J

Explanation:

From the question, we are informed that when spring was wound, 100J of work was done but 15J escaped to the surrounding as heat.

Therefore, the change in internal energy of the spring will be calculated as:

ΔU = q + w

where, q = -15J

w = 100J

ΔU = -15J + 100J

= 85J

Answer:

Revolutions

Explanation:

Answer:

at a rate of deceleration of -15 kilometers per second

Explanation:

90/6=15

The rate of deceleration when a car goes from 90km/h to 0 in 6 seconds is 4.16m/s².

The rate of deceleration can be calculated by using the following formula:

d = v - u/t

Where;

d = 25 - 0/6

d = 4.16m/s²

Therefore, the rate of deceleration when a car goes from 90km/h to 0 in 6 seconds is 4.16m/s².

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Answer: tennis ball

Explanation:

Answer:

4.692m

Explanation:

The distance that this boy climbed = 12.0m

The velocity = 3.0m/s

We are to find how far forward this apple goes before it hits the ground.

We have y = 1/2gt²

X = v*t

T = 1.564 seconds

X = 3x1.564

X = 4.692m

Therefore the ball goes a distance of 4.692m forward before it then hits the ground.

Answer:

33.5 N

Explanation:

Given that

Mass of the sled is, m = 10 kg

Angle of slope, θ = 20°

The tension in the rope of its parallel to the slope is often given as

W * sinθ, where

W = Force on the rope and

θ = angle of the slope

Now, remember that

w = mg, where g = acceleration due to gravity, so

W = 10 kg * 9.81 m/s²

W = 98.1 N,

Going ahead to solve for tension in the slope, we have

T = W * sinθ

T = 98.1 * sin20

T = 98.1 * 0.342

T = 33.5 N

Tension in the slope is 33.5 N

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Answer:

The initial velocity of Billy is 66.6 m/s.

Explanation:

Given;

acceleration of Billy, a = 12.3 m/s²

distance moved by Billy, d = 455 m

final velocity of Billy, v = 125 m/s

let the initial velocity of Billy = u

Apply the following equation of motion;

v² = u² + 2ad

125² = u² + 2(12.3 x 455)

15625 = u² + 11193

u² = 15625 - 11193

u² = 4432

u = √4432

u = 66.57 m/s

u = 66.6 m/s.

Therefore, the initial velocity of Billy is 66.6 m/s.

[tex]\displaystyle v = 5.7735 \ m/s[/tex]

Math

Pre-Algebra

Order of Operations: BPEMDAS

Equality Properties

Physics

SI Units

Energy

Kinetic Energy Formula: [tex]\displaystyle KE = \frac{1}{2} mv^2[/tex]

Step 1: Define

Mass m = 30 kg

Kinetic Energy KE = 500 J

Step 2: Solve for v

Answer:

electrical

Explanation:

the TV needs electrical energy to power on

Answer:

electrical energy powers your TV, computer, microwave and toaster.

Answer:

Laws

Explanation:

Laws are a primary way discourage drinking and driving

A primary way to discourage drinking and driving is Law.

The person who takes in alcohol and then drives on the road. This is strictly prohibited.

Laws against the  'drinking and driving' will make people get scared of getting charged or sentenced to jail for some years. Lot of accidents have caused when there were no laws against the action.

Thus, Laws are a primary way to discourage drinking and driving.

Learn more about drinking and driving.

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Answer: the answer is 19cm

Explanation:

Answer:

1. The respiratory system functions when our involuntary nervous system sends impulses to the muscles in the diaphragm; thereby, causing the lungs to expand and contract.

2. The respiratory system oxygenates the blood which is vital for bodily function as oxygenated blood is carried from your lungs to the left side of your heart, to be circulated throughout the body. Furthermore deoxygenated blood is carried back to the right side of your heart to get oxygenated once more.

3. The other body systems that are crucial for the lungs to function are the nervous system and the muscular system.

4. without the raspatory system the body wouldn't receive any oxygen and the brain would slowly die. therefore, without the brain the heart would stop functioning and atrophy etc.

Explanation:

Answer:

a)     F _total = 15.08 10⁻³ N ,   b)   m = 1,539 10⁻³ kg

Explanation:

a) To solve this problem we can use Coulomb's law to find the force created by each charge

          F =[tex]k \frac{\ q_{1} q_{2} }{r_{12}^{2} }[/tex]

and the total force is

          F = F₁₅ + F₂₅ + F₃₅ + F₄₅

The bold are vectros, In the exercise they indicate the charges

          q₁ = q₂= q₃ = q₄ =  1 10⁻⁶ C

          q₅ = 2 10⁻⁶ C

Let's set a reference system where the sphere is on the z axis and the other charges on the xy plane, let's write the coordinates of card charge

sphere (subscript 5)

   x₅ = 0

   y₅ = 0

   z₅ = 2 m

charge 1

   x = 0.5 m

   y = 0.5 m

   z = 0

charge 2

   x = -0.5 m

   y = 0.5 m

   z = 0

charge 3

   x = -0.5 m

   y = -0.5 m

   z = 0

charge 4

   x = 0.5 m

   y = -0.5 m

   z = 0

With these values ​​we can calculate the distance between each charge and the sphere

charge 1 and sphere

       r₁₅² = (x₅ -x₁)² + (y₅ - y₁)² + (z₅ -z₁)²

substitute

       r₁₅² = (0- 0.5)² + (0 - 0.5)² + (2 -0)²

       r₁₅² = 0.5² + 0.5² + 2²

       r₁₅² = 4.5

we can see that for the other charges the result is the same since being squared always gives positive

      r₁₅ = r₂₅ = r₃₅ = r₄₅

the force created by the card charge on the sphere is the projection on the Z axis of the total force

Let's find the angle with respect to the Z axis

            tan φ = r / z

where r is the magnitude of the vector in the xy plane

          r = [tex]\sqrt{0.5^{2} + 0.5^{2} }[/tex]

          r = 0.7071 m

         φ = tan⁻¹ r / z

         φ = tan⁻¹ (0.7071 / 2)

         φ = 19.5

consequently the total force is

        F_total = 4 F cos 19.5

        F _total =   [tex]4 \frac{k \ q_{1} q_{5} }{r_{15}^{2}}[/tex]   cos 19.5

let's calculate

        F_toal = 4 9 10⁹ 1 10⁻⁶ 2 10⁻⁶ /4.5    cos 19.5

        F _total = 15.08 10⁻³ N

b) For this part indicate that the sphere is in equilibrium with the weight

           F_total - W = 0

           W = mg

           F_total = mg

           m = F_total / g

           m = 15.08 10³ / 9.8

           m = 1,539 10⁻³ kg

Answer:Detergent mixes with water to remove dirt and oil from clothes. Water can't remove oil and dirt from clothes. Detergent cleans by causing a chemical reaction with water to force dirt and debris out of clothing. Detergents work with water to loosen the dirt trapped in the material of clothing and clean them away.

Explanation:May i plz have brainlist only if u wanna give me brainlist though have an nice day!

Explanation:

Given parameters:

Height  = 5m

Mass of Sue  = 50kg

Unknown:

Magnitude of Sue's weight  = ?

Work done by Sue = ?

Solution:

Weight is the vertical force exerted by a body in the presence of gravity.

Mathematically;

        W = mg

m is the mass

g is the acceleration due to gravity  = 9.8m/s²

  Weight  = 50 x 9.8  = 490N

Work done  = Force x distance = weight x height

 Work done  = 490 x 5 = 2450J

Answer:0.4 m

Explanation:

Given

Maximum displacement A=0.49

The sum of kinetic and elastic potential energy is [tex]\frac{1}{2}kA^2[/tex]

where k=spring constant

U+K.E.=[tex]\frac{1}{2}kA^2[/tex]

when K.E.=U/2

K.E.=kinetic energy

U=Elastic potential Energy

[tex]\rightarrow \ U+\frac{U}{2}=\frac{1}{2}KA^2\\\rightarrow \ \frac{3U}{2}=\frac{1}{2}KA^2\\\rightarrow \ U=\frac{1}{3}KA^2\\\rightarrow \ \frac{Kx^2}{2}=\frac{1}{3}KA^2\\\\x=\sqrt{\frac{2}{3}}A\\x=0.4\ m[/tex]

Answer:

Explanation:

The potential energy of a body can be found by using the formula

PE = mgh

where

m is the mass

h is the height

g is the acceleration due to gravity which is 9.8 m/s²

From the question we have

PE = 20 × 9.8 × 2

We have the final answer as

Hope this helps you

Answer:

A. They are moving at 60 mph

Explanation:

When looking at the car on the track pass by, the people inside appear to be moving at the same speed as the car. So if the car is going 60 mph, the people instead will appear as though they are moving at 60 mph as well.

Answer:

Ro = 8.65 [g/cm³]

Explanation:

We must remember that density is defined as the ratio of mass to volume.

[tex]Ro=m/V[/tex]

where:

m = mass = 0.450 [kg] = 450 [g]

V = volumen = 52 [cm³]

Ro = density [g/cm³]

Now replacing:

[tex]Ro = 450/52\\Ro = 8.65 [g/cm^{3} ][/tex]

Answer:

[tex]\frac{dh}{dt}=-0.4125 m/s[/tex]

Explanation:

The very first thing we can do here is to draw a sketch of the situation the problem is presenting. (See attached picture)

As you may see in the picture, we can suppose the spotlight is directly located on the ground so the light of the spotlight together with the person and the wall make two similar triangles.

In this case we need to think about the dimensions of the triangle that will change over time. We will call them:

x= distance between the spotlight and the man.

h= height of the shadow.

So we can build a relation between the height and the length of each triangle:

[tex]\frac{h}{12}=\frac{2}{x}[/tex]

the distance between the spotlight and the wall is constant, so I can directly write the 12 in my equation and the height of the man is constant as well, so I can write the 2 directly into the equation.

Next, we can solve the equation for h (since we are interested in figuring out how fast the height of the shadow is decreasing) so we get:

[tex]h=\frac{24}{x}[/tex]

So next, we need to take the derivative of the equation, since the derivative of a position function will give us the velocity at which that position is changing.

First we rewrite the equation like this:

[tex]h=24x^{-1}[/tex]

and take the derivative:

[tex]dh=-24x^{-2}dx[/tex]

we can rewrite the derivative like this:

[tex]\frac{dh}{dt}=-\frac{24}{x^{2}} \frac{dx}{dt}[/tex]

where:

dh/dt is the velocity at which the height of the shadow is decreasing (that's why our equation has a negative sign in front of it).

dx/dt is the velocity at which the value of x is increasing. In other words, how fast the man is moving away from the spotlight.

So we can go ahead and substitute:

we wish to find the velocity at which the shadow's height is decreasing when the distance between the man and the building is 4m, so in this case, x=12-4=8m

[tex]\frac{dh}{dt}=-\frac{24}{8^{2}}(1.1 m/s)[/tex]

so we get:

[tex]\frac{dh}{dt}=-0.4125 m/s[/tex]

Answer:

9.23m

Explanation:

Max height = u²sin²theta/2g

u is the speed = 34.7m/s

theta is the angle of elevation = 33°

g is the acceleration due to gravity = 9.8m/s²

Substitute into the formula

Max height = 24.7²sin²33/2(9.8)

Max height = 610.09sin²33/2(9.8)

Max height = 610.09(0.29663)/19.6

Max height = 180.97/19.6

Max Height = 9.23m

Hence the max height the football reaches during flight is 9.23m

Answer:

t = 3/8 seconds

Explanation:

h=-16t^2 - 10t+6

h= 0 when it hits the ground

0=-16t^2 - 10t+6

factor out a -2

0= -2(8t^2 +5t -3)

divide by -2

0 = (8t^2 +5t -3)

factor

0=(8t-3) (t+1)

using the zero product property

8t-3 = 0    t+1 =0

8t = 3         t= -1

t = 3/8     t= -1

t cannot be negative  ( no negative time)

t = 3/8 seconds