PhysicsLAB: MCAS 2025 Session 1

MCAS Physics Exams
MCAS 2025 Session 1

A circuit with a battery and resistor is shown.

Which of the following best describes what happens to the circuit when the voltage is increased to 12 V?

A The current increases to four times the original value.
B The current decreases to one-quarter the original value.
C The resistance increases to four times the original value.
D The resistance decreases to one-quarter the original value.

A student pushed an object across a table to the right. The graph shows the velocity of the object over time during three time intervals, X, Y, and Z.

Which of the following sets of free-body force diagrams best represents the forces acting on the object during time intervals X, Y, and Z?

Students are studying momentum using a baseball and a softball. The students measure the mass of each ball. Then the students roll the baseball toward the softball and measure the velocity of each ball after the balls collide.

Which of the following shows how the students can calculate the final momentum of the system after the balls collide?

Two waves, X and Y, are traveling toward each other. The waves cancel each other out when they interact and completely overlap.

Which of the following diagrams best represents the two waves before they interact?

Some older forms of computer technology used plastic discs coated with iron oxide to store information in magnetic fields. Which of the following best explains why one of these discs could be damaged if placed near a coil of wire

that is carrying current?

A The coil of wire generates heat, which could charge the iron oxide coating.
B The coil of wire uses energy, which could affect the energy stored in the iron oxide coating.
C The current in the wire produces a gravitational field, which could pull the iron oxide coating off the disc.
D The current in the wire produces a magnetic field, which could alter the magnetic storage in the iron oxide coating.

A 12 kg object and a 16 kg object are located 2 m apart. Each exerts a gravitational force, F_g, on the other, as shown in the diagram.

Which of the following pairs of objects placed 4 m apart will have these same gravitational forces?

A circuit with a battery and four resistors is shown.

Part A: Which resistor has the greatest voltage drop across it?

A 8 ΩB 10 ΩC 12 ΩD 18 Ω

Part B: What is the current through the 10 Ω resistor?

A 0.25 A

B 0.83 A

C 1.2 AD 4 A

A student compresses a spring with a block, as shown in the diagram.

When the student lets go of the block, the block moves to the right, as shown in the diagram below.

Which of the following describes a change in energy that occurs when the student lets go of the block?

A The total energy of the system increases as the moving block creates kinetic energy.
B The total energy of the system decreases as kinetic energy changes into potential energy.
C The potential energy of the block increases as the kinetic energy of the spring decreases.
D The potential energy of the spring decreases as the kinetic energy of the block increases.

The magnetic fields between three pairs of magnets are shown. One magnet in each pair is labeled X, Y, or Z.

Part A: Which of the following shows the orientation of bar magnet X?

Part B: Which of the following shows the orientation of bar magnet Y?

Part C: Which of the following shows the orientation of bar magnet Z?

A glass lens improves eyesight by changing how light travels from air into the glass lens.

Part A: As light travels from air into the glass lens, the frequency of the light remains the same. As light moves from air into the glass lens, the light’s period

A changes.B does not change.

Part B: As light moves from air into the glass lens, the light’s speed

A changes.B does not change.

Part C: As light moves from air into the glass lens, the light’s wavelength

A changes.B does not change.

Part D: Which of the following models best shows how light travels from air into the glass lens?

Two free-body force diagrams are shown.

Which of the following could be represented by these diagrams?

A Two sleds are sliding down a hill together.
B Two cars are parked in the same driveway.
C Two large magnets on a table are repelling each other.
D Two charged balloons hanging from strings are attracting each other.

The International Space Station (ISS) orbits Earth at an average distance of 6.8 × 10⁶ m from the center of Earth, as shown in the diagram.

The mass of the ISS is 4.2 × 10⁵ kg, and the mass of Earth is 6.0 × 10²⁴ kg. What is the magnitude of the average gravitational force that acts on the ISS?

A 4.0 × 10^–14 NB 4.0 × 10^–3 NC 3.7 × 10⁶ ND 3.7 × 10²³ N

A student shines a laser through a piece of cardboard that has two slits in it. The light travels through the slits, spreads out and overlaps, and produces a pattern on a screen, as shown.

Which of the following best describes what causes the pattern on the screen when a crest of a wave of light traveling through one slit overlaps with a crest of a wave of light traveling through the other slit?

A The crests refract to form one of the dark lines in the pattern.
B The crests reflect to form one of the dark lines in the pattern.
C The crests destructively interfere to form one of the bright lines in the pattern.
D The crests constructively interfere to form one of the bright lines in the pattern.

The following section focuses on energy conversions that occurred when a ball bounced on a trampoline.

Read the information below and use it to answer the selected-response questions and constructed-response question that follow.

Students used a trampoline and a ball to investigate energy conversions. The trampoline is shown in the diagram.

The students dropped a 5 kg metal ball onto the trampoline. The diagram below shows the positions of the ball during the investigation.

The ball was dropped from position 1 and was just above the trampoline at position 2. When the ball collided with the trampoline, both the fabric and springs stretched as the ball continued to move downward. The ball momentarily stopped at position 3, and then began moving upward as the fabric and springs returned to their original position. The ball was just above the trampoline at position 4 and continued to move upward to position 5.

The students recorded the ball’s speed, height, and direction of motion at each position. The data are shown in the table.

In which of the following positions did the ball have the greatest momentum?

A position 1B position 2C position 3D position 4

What was the gravitational potential energy of the 5 kg ball when it was at position 4?

A 9.1 JB 19.6 JC 32.5 JD 50.0 J

Based on the data in the table, which of the following graphs best represents the gravitational potential energy (GPE) and kinetic energy (KE) of the ball at position 1 and at position 2?

Open-Response Questions

BE SURE TO ANSWER AND LABEL ALL PARTS OF THE QUESTION.
Show all your work (diagrams, tables, or computations) on the next page.
If you do the work in your head, explain in writing how you did the work.

Refer to the following information for the next three questions.

Question has three parts.

The collision time between the 5 kg ball and the trampoline was 0.175 s as the ball moved from position 2 to position 3.

Part A. Calculate the change in momentum of the ball as it moved from position 2 to position 3. Show your calculations and include units in your answer.

Part B. Calculate the average net force on the ball as it moved from position 2 to position 3. Show your calculations and include units in your answer.

Part C. Identify one change to the setup of the investigation that would reduce the average net force on the ball as it moved from position 2 to position 3. Explain your reasoning.