 MCAS Physics Exams MCAS 2010 Session 2 A 2000 kg car is pulling a 1000 kg trailer. The car’s engine exerts a 6000 N force to move the car and the trailer. In addition, the car and the trailer each experience a 1000 N frictional force as they are being pulled, as represented below. What is the magnitude of the net force on this system? A teacher asks a group of students to use a ruler to measure the amplitude of the wave shown below. Between which of the following points should the amplitude be measured? The diagram below represents a bicyclist at the top of a hill, with four points labeled W, X, Y, and Z. Assume that the bicyclist does not apply the brakes as he rides down the hill. At which point will the bicyclist’s kinetic energy be closest to zero? Which of the following is designed to produce an electromagnetic wave? Two full 2 L bottles of water are placed on a table. Bottle 1 was just removed from a refrigerator; bottle 2 is at room temperature.

Which of the following statements describes the average molecular kinetic energy and the speed of the molecules in each bottle? Which of the following statements describes a result of Earth’s gravitational pull on the Moon? A microwave oven uses 10 A of current when connected to a wall outlet that provides 120 V of electricity. What is the resistance of the microwave oven? Two students are standing next to each other on a level field. One of the students throws a table tennis ball forward toward a line 2.0 m away. At the same time, the second student throws a bowling ball in the same direction. Both balls take the same time to travel the 2.0 m.

Only the second student feels a noticeable backward push when she throws her ball.

Which of the following statements explains why only the second student feels a noticeable backward push? A copper sphere, a glass sphere, a plastic sphere, and a rubber sphere are placed on individual insulating stands. A student touches each sphere with an electrically charged object.

The sphere made of which material will distribute the electric charge fastest over its entire surface area? A person is using a force of 200 N to push a box. How much power does the person need to push the box a distance of 4 m in 10 s? Which of the following will always change when an object accelerates? In a television set with a cathode ray tube display, a beam of negatively charged particles called cathode rays passes by a positively charged plate. The beam is deflected before it hits the television screen to produce an image.

Which of the following changes would result in the greatest increase in the attraction between the negatively charged particles in the beam and the positively charged plate? Which of the following would cause a change in the speed of a mechanical wave? The table below shows the time it takes four cars to go from 0 to 60 km/h. Based on the information given, which of the following quantities can be compared for the four cars? The diagram below shows a light ray striking the flat surface of a piece of clear hard plastic at an angle of 45°. Light travels faster in air than through plastic. Which of the following diagrams shows how the ray is refracted after it travels through the plastic? The graph below shows the speed of an object during a 10 s time interval. In which of the following time intervals is the speed of the object decreasing? A string is tied on a spring. Two students then stretch out the spring, as shown below. In which of the following ways does the string move when the students generate a longitudinal wave in the spring?

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 three questions. When some elements are put into a flame, they emit colored light. Yellow light is emitted from one element and violet light is emitted from another element.

 a. Describe the differences between yellow light and violet light in terms of frequency and wavelength.

 The diagram below represents violet light. b. Copy the diagram of violet light into your Student Answer Booklet. Below your diagram, draw and label a representation of yellow light that illustrates how its frequency and wavelength are different from that of violet light.

 c. Yellow light and violet light are both in the visible range of the electromagnetic spectrum. Identify two other similarities between yellow light and violet light.

Refer to the following information for the next three questions. A pendulum is made with a bowling ball as the bob and a wire attached to the ceiling, as shown in the illustration below. The person in the illustration pulls the bowling ball back until it touches his nose, then releases the bowling ball. Assume that he does not move. a.  Describe the changes in the potential energy and the kinetic energy of the bowling ball as it swings back and forth.

 b.  Explain whether the bowling ball will hit the person’s nose. Include a discussion of energy changes in your explanation.

 c.  Explain what will happen if the person gives the bowling ball a small push as it is released. Include a discussion of energy changes in your explanation.

Refer to the following information for the next four questions. The diagram below shows a circuit with a 12 V battery connected in series with a 4 Ω resistor and a 2 Ω resistor. Two points in the circuit are labeled X and Y. 