A block has two strings attached to it on opposite ends. One string has a force of 5 N,
the other string a force of 15 N. The block is accelerating at 1 m/s2 on a horizontal surface.
A) What is the mass of the block if the friction force is 3 N?
B) What is the coefficient of friction?
Unless you have a diagram to include or any other additional info, I'll assume the block is being pulled by two opposing forces along the horizontal surface.
Horizontally, the block is under the influence of
• one rope pulling in one direction with magnitude 15 N,
• the other rope pulling in the opposite direction with mag. 5 N, and
• friction, opposing the direction of the block's motion, with mag. 3 N.
It stands to reason that the block is accelerating in the direction of the larger pulling force.
(A) By Newton's second law, we have
15 N + (-5 N) + (-3 N) = m (1 m/s²)
where m is the mass of the block. Solve for m :
7 N = m (1 m/s²)
m = (7 N) / (1 m/s²)
m = 7 kg
(B) The friction force is proportional to the normal force, so that if f is the mag. of friction and n is the mag. of the normal force, then f = µ n where µ is the coefficient of friction.
The block does not bounce up and down, so its vertical forces are balanced, which means the normal force and the block's weight (mag. w) cancel out:
n + (-w) = 0
n = w
n = m g
where g = 9.8 m/s² is the mag. of the acceleration due to gravity.
n = (7 kg) (9.8 m/s²)
n = 68.6 N
Then
3 N = µ (68.6 N)
µ = (3 N) / (68.6 N)
µ ≈ 0.044
A block has two strings attached to it on opposite ends. One string has a force of 5 N,
the other string a force of 15 N. The block is accelerating at 1 m/s2 on a horizontal surface.
A) What is the mass of the block if the friction force is 3 N?
B) What is the coefficient of friction?
Answer:
A) 7kg
B) 0.044
Explanation:
a) Accordimg to Newton's second law
\sum F = ma
Fm - Ff = ma
Fm is moving force =15-5 = 10N
Ff is fictional force = 3N
m is the mass = ?
a Is the acceleration = 1m/s²
Substitute
10-3 = 1m
7 = m
Hence the mass of the body is 7kg
b) coefficient of friction is expressed as;
n = Ff/R
R is the reaction = mg
n =Ff/mg
Substitute
n = 3/7(9.8)
n = 3/68.6
n = 0.044
Hence the coefficient of friction is 0.044
If you push against the wall the wall will push back what is the name of the force that pushes back?
tension force
Оа
Ob
Ос
normal force
applied force
friction force
Od
Answer:
applied force
Explanation:
I think that's right
A projectile is fired at a speed of 125 m/s toward a tall building. The building is a horizontal distance of 75 meters from the point where the projectile is launched. The projectile strikes the building 30 meters above ground level. Find the launch angle of the projectile.
Answer:
what is 30 + 40 add
Explanation:A softball player swings a bat, accelerating it from rest to 2.2 rev/srev/s in a time of 0.20 ss . Approximate the bat as a 2.3-kgkg uniform rod of length 0.96 mm , and compute the torque the player applies to one end of it.
Answer:
83.168 Nm
Explanation:
I=mass of bat* ( length )^2 /3
Moment of inertia from one end = 2.2 * (0.96)^2 / 3.
Ang. acc. = 2.2×2 pi / 0.2 = 22pi
Torque = 2.3 * (0.96)^2 / 3 * 22 pi = 83.168 Nm SI units
What is the conflict in this passage?
Tony worries about how to fight Felix without hurting him.
Tony cannot figure out how to get down from the roof.
Tony no longer wants to be friends with Felix.
Tony wants to figure out a way for both of them to win.
Answer:
the conflict in this passage is
Tony worries about how to fight Felix without hurting him.
it right i just took the test
The conflict sentence in the passage is, Tony worries about how to fight Felix without hurting him.
What is meant by conflict?Conflict can be meant as clash happened between one another of different individuals and they used to arise out for one's own process, their way of understanding and their interests and also it depends upon everyone's perception. Also, conflicts leads to physical abuse.
In the given sentences,
A. Tony worries about how to fight Felix without hurting him.
Here, there is a point to thinking about no physical abuses and loss of peace and harmony.
B. Tony cannot figure out how to get down from the roof.
In the above sentence Tony was just thinking an idea about how to come down from the roof. There will not be any clashes.
C. Tony no longer wants to be friends with Felix.
The above sentence was only about the relationship of Tony and Felix.
D. Tony wants to figure out a way for both of them to win.
This sentence is completely in the positive approach to attain success.
So, the correct answer is option A.
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If you apply an equal force to a larger mass, it will take longer to accelerate.
Tru or false
Answer:
true
Explication:
The acceleration of an object depends on the mass of the object, and the amount of force applied
what type of energy is kinetic energy? A nuclear energy B chemical energy C potential energy D mechanical energy
Answer:
I believe it is C, Potential
Explanation:
Google, since all types are either kinetic or potential, so it wouldn't make sense if kinetic was itself. I also know for a fact it isn't Chemical
What is the relationship between a planet’s distance from the sun and the length of its year? Explain.
Answer:
Planets that are close to the sun have shorter years, and planets that are farther have longer years, because of how fast/slow it orbits the sun.
Explanation:
Two particles each with a charge -Q are fixed a distance L apart . Each particle experiences a net electric force F. A particle with a charge +q is now fixed midway between the original two particles. As a result, the net electric force experienced by each negatively charged particle is reduced to F/2. The value of q is:_________.
A. Q
B. Q/2
C. Q/4
D. Q/8
E. Q/16
Answer:
B. Q/2
Explanation:
Given;
charge of the two particles, = -Q
distance between the two charges, r = L
the net force experienced by each charge = F
Apply coulomb's force between two charged particles;
[tex]F = \frac{KQ^2}{r^2} = \frac{kQ^2}{L^2}[/tex]
when
+q is introduced midway between the charges, the net force is reduced by 2
[tex]\frac{F}{2} = \frac{kQq}{L^2} \\\\ \frac{1}{2}(\frac{kQ^2}{L^2} ) = \frac{kQq}{L^2}\\\\\frac{kQ^2}{2L^2} =\frac{kQq}{L^2} \\\\\frac{Q}{2} = q[/tex]
Thus, The value of q is Q/2
The value of q is Q/2, when the net electric force experienced by each negatively charged particle is reduced to F/2.
Given here,
-Q = charge of the two particles
r = distance between the two charges = L
F = net force on each charge
From coulomb's force between two charged particles;
[tex]\bold{F = \dfrac {KQ^2}{r^2} =\dfrac {kQ^2}{L^2} }[/tex]
If +q is bring at mid point between the charges, the net force is reduced by 2
Thus, q = Q/2
Therefore, the value of q is Q/2, when the net electric force experienced by each negatively charged particle is reduced to F/2.
An elf pushes a sleigh with force of 9N over a distance of 11m. How much work did the elf. Do on the sleigh
Answer:
99 JExplanation:
The work done by an object can be found by using the formula
workdone = force × distance
From the question we have
workdone = 9 × 11
We have the final answer as
99 JHope this helps you
A rocky meteoroid is on a collision course with planet Earth. The meteoroid is only 0.10 m in diameter.
The meteoroid will most likely not reach the surface of the Earth because
A.
it will be struck by lightning.
B.
it will collide with a shooting star.
C.
it will be intercepted by a space vehicle.
D.
it will burn up in the Earth's atmosphere.
Answer:
it will burn up in the Earth's atmosphere.
Explanation:
The structure of the Earth's atmosphere protects the surface from frequent meteoroid strikes. As a meteoroid enters the atmosphere from outer space, it moves at very high speeds. At such speeds, intense amounts of friction and heat result. This process usually causes small meteoroids to burn up in the Earth's atmosphere before ever reaching the surface.
True or False: An acid is a solution that has an excess of H+ ions.
Answer:
true
Explanation:
When does a battery give off the most gas, when charging has just begun or when the battery is almost fully charged?
Answer:
When the battery is almost fully charged.
Explanation:
A battery is a term used to describe any device that has the capability to convert chemical energy through an oxidation-reduction(redox) reaction taking place within the electrical circuit.
A battery usually have two ends, named as a cathode electrode(Positive) and an anode(negative) electrode. Batteries usually give off the most gas when they are almost fully charged, that is while it is advisable not to over charge a battery.
An irrigation system supplies water at a pressure of 0.5 MPa and flow rate of 5,000 liter per hour. If both the pump and motor are 100% efficient, what is the current required of a 220 volt service. Give your answer as a bare number in amps, with no units attached.
Answer:
3.16 A
Explanation:
The irrigation system has a motor which is used to drive the pump. The efficiency of the system is the ratio of the power output to power input. It is given as:
Efficiency = Power output / Power input
Given that efficiency = 100% = 1, flow rate = 5000 liter / hour = 0.00139 m³/s, pressure = 0.5 MPa = 0.5 * 10⁶ Pa, voltage = 220 V.
Power output = supply of the pump = flow rate * pressure
Power output = 695 W
Efficiency = Power output / Power input
1 = 695 / power input
Power input = 695 / 1
Power input = 695 W
Also, Power input = input of motor = voltage * current
Power input = voltage * current
695 = 220 * current
current = 695 / 220
current = 3.16 A
When we walk, our legs alternatively swing forward about the hip joint as a pivot. In this motion the leg is acting approximately as a physical pendulum. Treating the leg as a thin uniform rod of length 0.80 m, find the time it takes for the leg to swing forward.
Answer:
0.3 seconds
Explanation:
When we walk, our legs alternatively swing forward about the hip joint as a pivot. In this motion the leg is acting approximately as a physical pendulum. Treating the leg as a thin uniform rod of length 0.80 m,
To find the time it takes for the leg to swing forward, where g = 9.8 m/s^2
Let's use the simple pendulum formula which says that:
T = 2π( sqrt ( L/g))
T = 2π[sqrt (0.8/9.8)]
T = 2π × 0.082
T = 0.5129
For the leg to swing forward only, the number of complete oscillations will be half.
Period T = time t ÷ number of complete oscillations. That is,
T = t ÷ 1/2
0.5129 = t ÷ 1/2
t = 0.5129 × 1/2
Time t = 0.256 seconds.
Therefore, the time it takes for the leg to swing forward is 0.3 seconds approximately
although acceleration usually causes a change in speed what causes a change in direction?
A.centripetal force
B.angular velocity
C.radian(rad)
D.centripetal acceleration
Answer:
B.
Explanation:
Help me! Btw he’s playing golf.
Answer:
Muscular energy
Explanation:
Hope it helps!!!!
Can you find two ways that carbon can get from the ocean to the lithosphere?
Answer:
Two ways carbon can get from the ocean to the lithosphere is through the marine plants + animals (in the ocean) , sediments, petroleum then to the lithosphere.
Hope that helps!
4. A massless spring hangs from the ceiling, and a mass is hung from the bottom of it. The mass is supported
so that initially the tension in the spring is zero. The mass is then suddenly released. At the bottom of
its trajectory, the mass is 5 centimeters from its original position. Find its oscillation period.
(A) 0.05 s
(B) 0.07 s
(C) 0.31 s
(D) 0.44 s
(E) Not enough information is given.
Answer:
The correct option is C: 0.31 s.
Explanation:
When the mass is then suddenly released we have:
[tex] F = k\Delta y [/tex]
Where:
F is the force
k: is the spring constant
Δy: is the spring displacement
Since the tension in the spring is zero, the force is the weight:
[tex] F = mg [/tex]
Where:
m is the mass of the object
g is the gravity
[tex] mg = k\Delta y [/tex] (1)
The oscillation period of the spring is given by:
[tex] T = 2\pi \sqrt{\frac{m}{k}} [/tex] (2)
By solving equation (1) for "k" and entering into equation (2) we have:
[tex] T = 2\pi \sqrt{\frac{m}{\frac{mg}{\Delta y}}} [/tex]
[tex]T = 2\pi \sqrt{\frac{\Delta y}{g}}[/tex]
Since the spring will osclliates in a position between the initial position (when it is at rest) and the final position (when the mass is released and reaches the bottom), we have Δy = 2.5 cm = 0.025 m:
[tex] T = 2\pi \sqrt{\frac{0.025 m}{10 m/s^{2}}} = 0.31 s [/tex]
Hence, the oscillation period is 0.31 s.
The correct option is C: 0.31s.
I hope it helps you!
Unpolarized light with intensity 300 W/m^2 passes first through a polarizing filter with its axis vertical, then through a second polarizing filter. It emerges from the second filter with intensity 121 W/m^2. What is the angle from vertical of the axis of the second polarizing filter?
Answer:The value of the angle from vertical of the axis of the second polarizing filter is equal to 30.2°
Explanation:
If a boat and its riders have a mass of 1100 kg and the boat drifts in at 1.3 m/s how much work does Sam do to stop it
Answer:
-929.5Joules
Explanation:
To get the work done by sam, we will calculate the kinetic energy of sam expressed as;
KE = 1/2mv²
m is the mass = 1100kg
v is the velocity = 1.3m/s
KE = 1/2(1100)(1.3)²
KE = 550(1.69)
KE = 929.5Joules
Since Sam is opposing the direction of movement, work done by him will be a negative work i.e -929.5Joules
Difference between compressions and rarefactions
Answer:
Compression- a region in a longitudinal (sound) wave where the particles are closest together. Rarefaction- a region in a longitudinal (sound) wave where the particles are furthest apart.
Answer:
please mark as brainliest!!!!
Explanation:
Compression- a region in a longitudinal (sound) wave where the particles are closest together.
Rarefaction- a region in a longitudinal (sound) wave where the particles are furthest apart.
what does this weather map symbol represent, and what type of weather can typically
be expected when this symbol is shown?
A blue "H" means a center of high pressure (usually calm, sunny weather). A red "L" means low pressure (which can mean storminess). Most fronts extend from low-pressure centers.
The weather symbol blue 'H' represents high pressure while red 'L' represents Low pressure.
What is a weather symbol?Weather symbols can be described as symbols with which meteorologists indicate various atmospheric and natural conditions on special weather maps such as temperature, pressure, precipitation, wind, or the percentage of cloud coverage in the sky. These maps can be used to be paper maps or digital.
Warm fronts can be described as indicated by curved red lines with red semicircles. Cold fronts can be curved blue lines with blue triangles. Stationary fronts exhibit alternating red curves with semicircles and blue curves with triangles. There are 99 present weather symbols used in meteorology.
The eight elements observed by meteorologists for creating weather forecasts are air temperature, humidity, wind speed, wind direction, visibility, clouds, precipitation, and atmospheric pressure.
On weather maps, readings are represented as a red “L” for low pressure or a blue “H” for high pressure.
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A small plane starts from rest and accelerates uniformly to the east to a takeoff velocity of 70 m/s in 5 seconds. What is the plane’s acceleration?
A cooling fan is turned off when it is running at 850 rev/min . It turns 1350 revolutions before it comes to a stop. What was the fan's angular acceleration, assumed constant
Answer:
α = -0.47 rad/sec²
Explanation:
Assuming that the angular acceleration is constant, we can apply the following kinematic equation:[tex]\omega^{2}_{f} - \omega^{2}_o} = 2* \alpha* \Delta \theta (1)[/tex]
Since the fan comes to an stop, ωf = 0.In order to get the value of the angular acceleration in rad/sec2, we neeed to convert first ω₀ to rad/sec, and Δθ, to rad, as follows:[tex]\omega_{o} = 850 rev/min * \frac{2*\pi rad}{rev} * \frac{1min}{60 sec} = 89 rad/sec (2)[/tex]
[tex]\Delta \theta = 1350 rev *\frac{2*\pi rad}{1rev} = 8482.3 rad (3)[/tex]
Solving for α in (1):[tex]\alpha = \frac{-\omega_{o}^{2} }{2*\Delta\theta} = -0.47 rad/sec2 (4)[/tex]
A block slides at constant speed down a ramp while acted on by three forces: its weight, the normal force, and kinetic friction. Respond to each statement, true or false.
Answer:
a) True
b)False
c)False
• Had to complete the question first.
A block slides at constant speed down a ramp while acted on by three forces: its weight, the normal force, and kinetic friction. Respond to each statement, true or false.
(a) The combined net work done by all three forces on the block equals zero.
(b) Each force does zero work on the block as it slides.
(c) Each force does negative work on the block as it slides.
Explanation:
Net work is the change in kinetic energy, which leads to final kinetic energy - our initial kinetic energy this is the formula for net work. This is the working energy theorem, a theorem that states that the net work on an object induces a change in the object's kinetic energy.
How does air resistance affect how fast a feather falls?
Answer: Ain't its because how light the feather is ? It's not as heavy.
Explanation: With air resistance, acceleration throughout a fall gets less than gravity (g) because air resistance affects the movement of the falling object by slowing it down. ... Usually, resistance is not very high at low speed or for small or sharp objects (Google Source if needed to prove yours answer)
To initiate a nuclear reaction, an experimental nuclear physicist wants to shoot a proton into a 5.50-fm-diameter 12C nucleus. The proton must impact the nucleus with a kinetic energy of 2.30 MeV. Assume the nucleus remains at rest. With what speed must the proton be fired toward the target?
Answer:
[tex]V_1= 3.4*10^7m/s[/tex]
Explanation:
From the question we are told that
Nucleus diameter [tex]d=5.50-fm[/tex]
a 12C nucleus
Required kinetic energy [tex]K=2.30 MeV[/tex]
Generally initial speed of proton must be determined,applying the law of conservation of energy we have
[tex]K_2 +U_2=K_1+U_1[/tex]
where
[tex]K_1[/tex] =initial kinetic energy
[tex]K_2[/tex] =final kinetic energy
[tex]U_1[/tex] =initial electric potential
[tex]U_2[/tex] =final electric potential
mathematically
[tex]U_2 = \frac{Kq_pq_c}{r_2}[/tex]
where
[tex]r_f[/tex]=distance b/w charges
[tex]q_c[/tex]=nucleus charge [tex]=6(1.6*10^-^1^9C)[/tex]
[tex]K[/tex]=constant
[tex]q_p[/tex]=proton charge
Generally kinetic energy is know as
[tex]K=\frac{1}{2} mv^2[/tex]
Therefore
[tex]U_2 = \frac{Kq_pq_c}{r_2} + K_2=\frac{1}{2} mv_1^2 +U_1[/tex]
Generally equation for radius is [tex]d/2[/tex]
Mathematically solving for radius of nucleus
[tex]R=(\frac{5.50}{2}) (\frac{1*10^-^1^5m}{1fm})[/tex]
[tex]R=2.75*10^-^1^5m[/tex]
Generally we can easily solving mathematically substitute into v_1
[tex]q_p[/tex][tex]=6(1.6*10^-^1^9C)[/tex]
[tex]K_1=9.0*10^9 N-m^2/C^2[/tex]
[tex]U_1= 0[/tex]
[tex]R=2.75*10^-^1^5m[/tex]
[tex]K=2.30 MeV[/tex]
[tex]m= 1.67*10^-^2^7kg[/tex]
[tex]V_1= (\frac{2}{1.67*10^-^2^7kg})^1^/^2 (\frac{(9.0*10^9 N-m^2/C^2)*(6(1.6*10^-^1^9C)(1.6*10^-^1^9C)}{2.75*10^-^1^5m+2.30 MeV(\frac{1.6*10^-^1^3 J}{1 MeV}) }[/tex]
[tex]V_1= 3.4*10^7m/s[/tex]
Therefore the proton must be fired out with a speed of [tex]V_1= 3.4*10^7m/s[/tex]
For what absolute value of the phase angle does a source deliver 71 % of the maximum possible power to an RLC circuit
Answer: the absolute value of the phase angle is 28°
Explanation:
taking a look at expression for the instantaneous electric power in an AC circuit;
P = VI -------let this be equation 1
p is power, v is voltage and I is current;
for maximum power
P_max = V_rms × I_rms --------let this be equ 2
where P_max is the maximum power, V_rms is the rms value of voltage and I_rms is the rms value of current.
Also for average electric power in an AC circuit
P_avg = V_rms × I_rms × cos²∅ -------let this be equ 3
where P_avg is the average power and cos∅ is the power factor
now from equation 2; P_max = V_rms × I_rms
so p_max replaces V_rms × I_rms in equation 3
we now have
P_avg = P_max × cos²∅
so we substitute
expression for the given value of the average power is
P_avg = P_max × 75%
p_avg = P_max.78/100
for the expression of the average electricity in an AC circuit
P_max.78/100 = P_max × cos²∅
78/100 = cos²∅
to get the absolute value of phase angle
∅ = cos⁻¹ ( √(78/100))
∅ = cos⁻¹ ( 0.8832)
∅ = 27.969 ≈ 28°
Therefore the absolute value of the phase angle is 28°
We have that for the Question "For what absolute value of the phase angle does a source deliver 71 % of the maximum possible power to an RLC circuit"
It can be said that
[tex]45^o[/tex] of the phase angle is required to deliver 71 % of the maximum possible power
Power delivered to RLC circuit is given by
[tex]P = \frac{V^2}{Z}cos\theta\\\\P = I^2Zcos\theta[/tex]
Therefore,
[tex]Z = \sqrt{R^2 + (X_L-X_C)^2}[/tex]
Power delivered is maximum, therefore,
[tex]P_{max} = cos\theta\\\\71\% = cos\theta\\\\cos\theta = 0.71\\\\\theta = cos^{-1}0.71\\\\\theta = 44.76^o\\\\approximately 45^o[/tex]
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