The students conducted another trial with magnets. The new trial was similar to trial 2, except they pushed both carts toward each other at the same time and then released each cart. The bar graph shows the total energy in the system just after the students released the carts.

 

 

The carts came to a brief stop when they were closest together.

 

Which of the following bar graphs represents the amount of each type of energy in the system when the carts were closest together?

The students calculated the kinetic energy (KE) of each cart before and after the collisions in trial 1 and trial 2. The table shows the calculated values for both collisions.

 

 

Part A: Which of the following describes the momentum and kinetic energy of the system during the collision in trial 1?

Part B: Some of cart X’s kinetic energy was transformed into different kinds of energy when cart X collided with cart Y in one of the trials.

 

Select the two types of energy that cart X’s kinetic energy was transformed into.

Free response question #18 is provided below.

 

 

Three pairs of objects, X, Y, and Z, with different charges are shown. Each pair is separated by a different distance.

 

 

Which of the following correctly orders the pairs of objects from the least to the greatest amount of force between them?

Question has two parts. Sound waves can travel through brick and air.

 

Part A: A 400 Hz sound wave travels through a brick. The sound wave moves through the brick with a speed of 4,176 m/s.

 

What is the wavelength of the sound wave?

Part B:  Another 400 Hz sound wave is traveling through air.

 

Which of the following correctly compares the speed of the sound wave traveling through air to the speed of the sound wave traveling through brick?

A student released two objects at rest, W and X, from the same height above the ground. The table shows the masses of the objects and the height from which the student dropped them.

 

 

Which of the following describes object W’s kinetic energy just before both objects hit the ground?

The diagram represents the electric field around a positively charged object and a negatively charged object. Four locations, W, X, Y, and Z, are labeled in the diagram.

 

 

At which of the labeled locations would another positively charged object

experience the greatest net force?

The velocity of a bus is represented in the graph shown.

 

 

Which of the following best describes how the bus moves over time?

Two students created wave pulses, W and X, at the ends of a long flexible spring. The wave pulses moved toward each other, met in the middle of the spring, and then moved away from each other, as shown in the diagram.

 

 

Which of the following figures shows how the spring appeared when the wave pulses met in the middle?

Two carts with different masses are both moving to the right. The mass and initial velocity of each cart are shown in the diagram.

 

 

The carts collide and then stick together, as shown below.

 

 

What is the speed and direction of the carts after the collision?

In trial 1, cart X and cart Y collided and attached to each other. During the collision, each cart exerted a force on the other cart.

 

A. Compare the magnitudes of the forces that cart X and cart Y exerted on each other during the collision. Explain your answer.

The collision between cart X and cart Y occurred from 0.5 s to 0.6 s.

 

B. Calculate the acceleration of Cart X during the collision. Show your calculations and include units in your answer.

C. Calculate the magnitude of the force exerted on cart X by cart Y during the collision. Show your calculations and include units in your answer.

A student heats a 200 g sample of water from 20°C to 80°C. The specific heat of water is 4.18 J/g • °C.

 

A. Calculate the thermal energy absorbed by the water. Show your calculations and include units in your answer.

The student then boils the water.

 

B. Describe what happens to the temperature of the water as it boils. Explain your answer.

The student repeats the experiment, this time placing a small block of iron into another 200 g sample of water. The specific heat of iron is 0.45 J/g • °C. Both the iron and the water are initially at 20°C and are heated to 80°C.

 

C. Compare the amount of thermal energy absorbed by the water in this experiment with your calculation in Part A. Explain your answer.

D. Describe how repeating the second experiment with a block made of a material with a greater specific heat will affect the amount of time it takes to heat the block. Assume the blocks have the same mass.

A circuit diagram is shown above. Bulb X and bulb Y each have a resistance of 5 Ω.

 

A. Compare the brightness of bulb X to the brightness of bulb Y when the switch is open.

B. Describe what happens to bulb X and to bulb Y when the switch is closed.

Another bulb with a resistance of 5 Ω is added to the circuit at point Z. The switch is opened again.

 

C. Describe one way this circuit functions differently than the original circuit when the switch was open.

D. Calculate the current in this circuit with bulbs X, Y, and Z when the switch is open. Show your calculations and include units in your answer.

A. On the graph provided complete the free-body force diagram for the bookcase moving at a constant speed. Draw and label two arrows to represent the horizontal forces.

 

• Draw each arrow on the free-body force diagram.

• The length of an arrow represents the magnitude of the force.

• Label one arrow F_friction and the other arrow F_push to identify the force that each arrow represents.

 

B. Identify one change to the floor that would affect the amount of force required to move the bookcase at a constant speed. Explain how the change affects the amount of force required to move the bookcase.

C. Identify another change, this time to the bookcase, that would affect the amount of force required to move the bookcase at a constant speed. Explain how the change affects the amount of force required to move the bookcase.