 MCAS Physics Exams MCAS 2014 Session 1 A book weighing 18.0 N is lifted from the floor and placed on a shelf 1.5 m high. What is the minimum amount of work required to accomplish this task? Waves rock a boat in the middle of a pond. The boat moves up and down 10 times in 20 s. What is the period of the waves? What will happen when two objects with opposite electric charges are moved closer together? Which of the following examples includes a vector quantity? Which of the following forces allow a battery-powered motor to generate mechanical energy? Electrostatic air cleaners installed in hospitals use static electricity to reduce dust particles in the air. The neutral dust particles are attracted to positively charged ions sprayed into the air cleaners. Which of the following figures shows the charge distribution on the dust particle as it is attracted to the positively charged ions? A car is parked on a flat driveway. Which of the following is a free-body diagram for this car? A container of water with an initial temperature of 90°C is placed in a room where the temperature is 20°C. Which of the following statements describes what happens to the water over the next several hours? Which of the following statements describes an advantage of using a wooden spoon instead of a metal spoon to stir a pot of hot soup? The free-body diagram below represents all the forces acting on an object. What is the net force acting on this object? Neglecting air resistance, which of the following statements describes the change in energy of a diver who falls downward toward a swimming pool? The graph below shows the temperature of a sample of water as it is heated at a constant rate. Which of the following conclusions is best supported by the information in the graph? A loud alarm attached to a metal fence begins to ring. Student X has her ear against a pole of the fence while student Y stands away from the fence, as shown below. Both students are the same distance from the alarm. Which of the following statements explains what happens in this situation? The power supplied to a light bulb is 100 W. How much electrical energy is used by this light bulb in 20 s? A sound wave with a frequency of 1,700 Hz is traveling through air at a speed of 340 m/s. What is the wavelength of this sound wave? A toy truck powered by a battery is accelerating to the right. A string with negligible mass is attached to the truck. The diagram below shows the forces acting on the truck. If a child pulls the string to the left, what force must the child exert to make the toy truck move to the right at a constant velocity? Which of the following placements of two charges results in the greatest repulsive force? Sunscreen protects skin by absorbing harmful ultraviolet radiation from the Sun. Ultraviolet radiation has which of the following properties? A small object is placed in a room with a narrow mirror on the wall. Four positions in the room are labeled W, X, Y, and Z, as shown below. At which position should a person stand to see the reflection of the object in the mirror? What is the magnitude of the momentum of a 0.15 kg baseball moving at 25 m/s? The Moon was much closer to Earth 4.6 billion years ago. Which of the following statements describes the gravitational interaction of Earth and the Moon 4.6 billion years ago?

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 question. A circuit diagram is shown below.

In your Student Answer Booklet, draw this circuit diagram and add four identical light bulbs (W, X, Y, and Z), two switches (S1 and S2), and two fuses (F1 and F2). Your arrangement of these components must meet the requirements listed below. Be sure to read all of the requirements before adding the electrical components.

• Light bulbs W and X have the same brightness.
• Light bulbs Y and Z have the same brightness and are brighter than light bulbs W and X when all switches are closed.
• The first switch (S1) controls only light bulbs W and X, and the second switch (S2) controls only light bulbs Y and Z.
• The first fuse (F1) protects only light bulb Z, and the second fuse (F2) protects the entire circuit.

 Use the circuit components shown below. Be sure to label all of the components with the labels given. Refer to the following information for the next three questions. Waves can be classified as either electromagnetic or mechanical.

 a. Describe two differences between electromagnetic and mechanical waves.

 b. Give two examples of electromagnetic waves.

 c. Give two examples of mechanical waves.