Phy 111 Final

A student attaches a 2.0 kg mass to a spring with a spring constant of 70 N/m. The student stretches the spring 0.15 m and then releases the spring. The spring-mass system oscillates horizontally on a frictionless surface. What is the position of the mass at time 1.5 s?

-0.12 m

What mass m2 will allow the following mobile to maintain static equilibrium?

0.075 kg

A 0.15 kg arrow moving with an initial velocity of 30 m/s passes through a 3.0 kg block initially at rest on a frictionless surface. If the final speed of the arrow is 25 m/s, what is the speed of the block?

0.25 m/s

A pendulum with a mass of 0.8 kg and a rope length of 1.2 m is angled at 20° relative to the vertical. What is the pendulum's oscillation frequency once it is released?

0.5Hz

What depth of water (density = 1000 kg/m3) will result in a fluid pressure of 5000 Pa?

0.5m

A spring with a mass of 0.5 kg and a spring constant of 40 N/m is compressed 0.35 m. When released, the spring-mass system will oscillate horizontally on a frictionless surface. What is the period of oscillation?

0.7s

A spring with a mass of 7.0 kg and a spring constant of 200 N/m is compressed 0.7 m. When released, the spring-mass system will oscillate horizontally on a frictionless surface. What is the frequency of oscillation?

0.85Hz

A student sets a board to pivot about its center. The student then places a box with mass m at some position r from the pivot point. The student plans to place a second box with mass 2 m on the other side of the board. In terms of r, where should the box be placed in order to maintain static equilibrium?

1/2r

A student measures the fluid pressure at the bottom of a column of fluid at 5.0 kPa. The atmospheric pressure is 101 kPa. What is the absolute pressure?

106kPa

What mass attached to a spring with a spring constant of 50 N/m will have an oscillation period of 3.0 s?

11.4 kg

A student hangs a 10 kg sign from the end of a 1.5 m long pole attached to a wall. What is the torque of the sign on the pole?

147 m-N

While pulling a nail out of a board, a student applies a downward 25 N of force on a crowbar at a position 0.2 m horizontal from the pivot point. The nail is located 0.03 m measured horizontal from the pivot point. What is the force of the crowbar on the nail?

168 N

A baseball bat collides with a 0.145 kg baseball moving with an initial velocity of 35 m/s to the left. If the collision lasts 0.005 seconds and the final velocity of the ball is 25 m/s to the right, what was the force of the bat on the ball?

1740 N

A 25 kg child rides a 3.0 kg skateboard with an initial velocity of 2.0 m/s. The child jumps backward off the skateboard in such a way that she has no final velocity. What is the resulting speed of the skateboard?

18.7 m/s

A 15 kg ladder with a length of 2.0 m is placed against a smooth wall. The ladder forms an angle of 75° relative to the ground. What is the friction force on the ladder?

19.7N

What is the fluid pressure at the bottom of a 2.0 m column of water (density = 1000 kg/m3)?

19600 Pa

A student creates a position vs. time graph for the oscillation of an object. The equation for the graph is determined to be: x = (0.25 m) cos (3.0 t) What is the period of oscillation?

2.1s

What is the buoyant force on a sphere that has half its volume submerged in water (density = 1000 kg/m3) if the radius of the sphere is 0.1 m? (Vsphere = 4/3πr3, SAsphere = 4πr2)

21 N

A student measures the fluid pressure at the bottom of a column of fluid at 3.0 kPa. The atmospheric pressure is 101 kPa. What is the gauge pressure?

3 kPa

What is the maximum velocity of a pendulum that has a starting height 0.5 m above the equilibrium?

3.1m/s

What net torque is required to make a solid 50 kg disk (I = ½ mr2) with a radius of 0.7 m experience an angular acceleration of 30 rad/s/s?

368m-N

2.0 kg bar with a length of 1.4 m is attached to a wall with a swivel mount. A 5.0 kg mass is suspended from the bar at a position 0.8 m from the pivot. The other end of the bar is held by a rope, which is attached vertically to the ceiling. What is the tension force in the rope?

37.8 N

A student fills an 80 kg wheelbarrow with 250 kg of material. The center of mass for the wheelbarrow is located at a point 0.1 m measured horizontally from the wheel. The center of mass of the added load is located 0.2 m measured horizontally from the wheel. What is the upward force of the student on the handle if the student's force is a horizontal 1.3 m from the wheel?

437 N

An object is suspended from a spring scale. The scale reads the weight of the cube at 20 N. The cube is then submerged in water while still attached to the scale, which now reads 15 N. What is the buoyant force on the object?

5 N

A solid 50 kg disk (I = ½ mr2) with a radius of 0.7 m rotates from rest to a final angular velocity of 20 rad/s in 4.0 seconds. What is the disk's angular acceleration?

5.0 rad/s/s

A cube is suspended from a spring scale. The scale reads the weight of the cube at 15.0 N. The cube is then submerged in water (density = 1000 kg/m3) while still attached to the scale, which now reads 10.0 N. What is the volume of the cube?

5.1x10-4 m3

Osmium is the densest element at 22590 kg/m^3. What is the mass of 0.25 m3 of osmium?

5648 kg

A simple, uniform bridge has a length of 8.0 m and a mass of 15000 kg. What is the normal force of the ground on the LEFT side of the bridge when a 1200 kg car is at a position of 6.0 m on the bridge?

7.6x104 N

A student pushes on a door with a force of 15 N at an angle of 70° relative to the door. If the student's force is located 0.6 m from the hinges, what is the torque on the door?

8.5 m-N

Use the following mercury barometer (density = 13560 kg/m3) to determine pressure of the gas surrounding the barometer. h= 0.7m

93 kPa

Which of the following changes will result in a larger period for a pendulum?

An increase in the length of the rope of the pendulum

A student allows a mass attached to a spring to oscillate back and forth for 10 seconds, which results in the following position vs. time graph. What effect would switching out the spring for a new spring with a larger spring constant have on the graph? (Assume that the starting position is the same for both springs.)

An increase in the number of waves measured in 10 seconds

Which of the following changes will result in a larger frequency for an oscillating spring-mass system?

An increase in the spring constant

A 1.0 kg piece of putty initially moves with a velocity of 1.0 m/s to the right. The putty collides with and sticks to a 5.0 kg ball initially at rest. Assuming negligible friction, which of the following best describes the momentum of the system after the collision?

Equal to 1.0 kg-m/s

A student sets a 0.4 kg meter stick to pivot at the 0.8 m mark. At what position should the student suspend a 0.2 kg mass to keep the system in static equilibrium?

Not possible at any position (Static equilibrium cannot be maintained with these conditions.)

A bug splats against the windshield of a car traveling at high speeds down a backcountry road. Which statement correctly compares the objects' changes in momentum?

The bug's change in momentum is equal to the car's change in momentum.

A student places a block of wood in a bucket of water where the block floats half above the surface. The student then places a second, larger block of wood in the bucket. The second block of wood also floats half above the surface. Which of the following statements is accurate?

The buoyant force on the larger block of wood is greater than the buoyant force on the smaller block of wood.

A pendulum is allowed to oscillate with some period T. The pendulum is then put into an elevator, which accelerates downward. Compare the new period of oscillation to the original.

The new period is greater than the original.

A spring-mass system is allowed to oscillate vertically. The period of oscillation is measured as T. The system is then brought into a low orbit around the Earth. Compare the new period of oscillation to the original.

The new period is the same as the original.

A student uses a lever to lift a massive object. The student finds that she has to apply a very large force. Which of the following changes will allow the student to use a smaller force while still lifting the object?

The student should angle the force so that it is perpendicular to the lever.

A student uses a wrench to apply a torque to a bolt. Which of the following changes will increase the magnitude of the torque?

The student should apply the force at an angle perpendicular to the wrench.

A student uses a wrench to tighten a particular bolt. Which of the following changes would allow the student to use a smaller force without changing the torque?

The student should move his hand further away from the bolt.

Which of the following statements concerning the simple harmonic motion of a pendulum is accurate?

The total energy in the system remains constant throughout the oscillations.

A student rides on a moving train and hears the train whistle at some frequency. Later, the student is standing on a platform and hears the whistle from the same train at a lower frequency. This is most likely because:

The train is moving away from the student causing the sound waves to stretch out.

Two blocks moving along a frictionless surface collide in an elastic collision. Which of the following correctly indicates the values that will be conserved in this collision?

Total momentum and total kinetic energy

Loudness is determined by a sound wave's

amplitude

A wheel, initially at rest, experiences a constant non-zero net torque. While the constant net torque is applied, the wheel will also experience a constant

angular acceleration.

A car turns a corner at a constant speed. Which of the following correctly identifies all of the non-zero acceleration terms experienced by the car?

centripetal

A student compares the fundamental resonating frequencies of two equal length pipes. Pipe A is open on both ends. Pipe B is open on one end and closed on the other. How does the frequency of pipe A measured at fA compare to the frequency of pipe B measured at fB?

fA = 2fB

A student attaches a 3.0 kg mass to a spring with a spring constant of 40 N/m. The student compresses the spring to the left by 0.15 m and then releases the mass allowing it to oscillate. Which of the following equations best describes the position vs. time relationship?

x = (-0.15 m) cos (3.65 t)

Which of the following are conditions for equilibrium?

Στ = 0