MCAS Physics Exams MCAS 2013 Session 2
The graph below represents the motion of an object over four time intervals,

Over which time interval is the object moving the fastest?

Which of the following observed properties of a wave is changed by the Doppler effect?
A person starts driving and travels 3 km east to a store. The person then turns around and travels 1 km west to another store. Finally, the person travels 2 km west, back to the starting point. What distance has this person traveled?
A 2-m long pendulum swings back and forth 6 times in 17 seconds. What is the period of the pendulum?
The diagram below shows two students making a wave with a coiled spring.

Which of the following waves move most like the wave in the coiled spring?
A student researches Jupiter and Saturn and records the following information:

• Jupiter is about half the distance to the Sun that Saturn is.
• Jupiter is about three times more massive than Saturn.

Based on this information, which of the following can be concluded about the gravitational forces between these planets and the Sun?

Which of the following substances has the lowest average molecular kinetic energy?
The diagram below shows a ball tied to a string. A student is swinging the ball in a horizontal circle.

If the student releases the string, in which direction will the ball travel?
Which of the following always occurs when a light ray reflects off a mirror?

Two positively charged objects are separated by a large distance. One of the positively charged objects is replaced by a negatively charged object, and the two objects are moved closer to each other. Which of the following occurs in this situation?

Calorimeters are instruments used to measure heat. The diagrams below show a calorimeter before a metal sample is added and after the sample is added.

Which of the following statements describes the flow of heat energy after the metal sample is added?

The potential energy of a 77 kg diver standing on a 20 m high diving tower is 15,400 J. Two-thirds of the way down during the dive into the pool, his potential energy is 5,100 J. Neglecting air resistance, what is the diver’s kinetic energy at this point?
Which of the following has the greatest momentum?

What method of heat transfer allows the Sun’s heat energy to reach Earth through the vacuum of space?
A current of 2 A passes through an 8 V load. What is the potential difference across the load?
Sound travels through air, steel, and water at different speeds. Which list is ordered from the substance that sound will travel through the slowest to the substance that sound will travel through the fastest?
The graph below illustrates the motion of a toy car during time intervals X, Y, and Z. The toy car is initially at rest. It is then pushed and released.

Kinetic friction is acting on the toy car during which of the following time intervals?
Work is performed on an object by raising it 2 m above the floor. Which of the following types of energy must change in this situation?
A worker in a warehouse pushes two wooden boxes across a floor at a  constant speed, as shown in the diagram below.

The arrow in the diagram represents the force box 1 exerts on box 2. Which arrow represents the reaction force?

Open-Response Questions
• BE SURE TO ANSWER AND LABEL ALL PARTS OF THE QUESTION.
• If you do the work in your head, explain in writing how you did the work.

Refer to the following information for the next four questions.

A student leaves school and walks south, arriving home after 18 min. The distance between the school and her home is 1200 m. At home, the student realizes she left a book at school. She walks back, arriving at the school 18 min later.
 a. Determine the student’s average speed as she walks home. Show your calculations and include units in your answer.

 b. Describe the difference between the student’s average velocity walking home and her average velocity walking back to the school.

 c. Calculate the total distance the student walked. Show your calculations and include units in your answer.

Refer to the following information for the next four questions.

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.

Refer to the following information for the next three questions.

The diagram below is a simplified representation of the inside of a certain type of camera.

 a. Identify and describe the wave behavior as the light rays pass through the glass lens.

 b. Identify and describe the wave behavior as the light rays strike the mirror.

 c. Copy the dotted box from the camera diagram into your Student Answer Booklet. Draw what must happen inside the box for light ray 2 to strike the viewfinder. Be sure to include the following:   either a lens or a mirror that is labeled the path of light ray 2 a line normal to the surface where light ray 2 strikes