 MCAS 2013 Session 1 Printer Friendly Version A rope is attached to a block that has a weight of 120 N. When the rope exerts an upward force of 250 N on the block, what is the net force on the block? A student is shaking one end of a small rug with a ball on top of it. The wave that is produced travels through the rug and moves the ball upward, as shown in the diagram below. Which type of wave is produced in the rug? A student has a circuit that is missing a component at location X, as shown in the diagram below. The student wants component Y to warm up after the switch is closed. Which of the following components should the student add to the circuit at location X? A satellite in a circular orbit around Earth has a constant speed but not a constant velocity. Which of the following statements best explains why the satellite’s velocity is not constant? An object is traveling in a straight line. The graph below shows the object’s velocity over time. Which line segment shows the object traveling with a constant, positive acceleration? A person is driving north in a car at a constant speed. A police officer is driving south toward him at a constant speed. The police officer uses a radar unit to measure the speed of the person’s car. The radar unit sends out waves of a certain frequency toward the person’s car. The waves reflect off the person’s car and travel back to the radar unit in the police car.

What happens to the frequency of the waves detected by the radar unit? A student slowly heats a beaker of a liquid on a hot plate. The liquid has a boiling point of 78°C. The student makes the graph shown below from the data she records as the liquid is heating. Which of the following statements best describes what happens to the molecules of liquid between 5 and 10 minutes of heating? Which of the following statements describes an electric generator? A neutral balloon is rubbed with a piece of wool cloth. As a result, the balloon has a negative static charge. Which of the following statements best
explains why the balloon has a negative charge? What is the magnitude of the momentum of a 0.50 kg ball moving in a straight line at 5.0 m/s? The human ear is most sensitive to sound that has a frequency of about 4000 Hz. Assume that the speed of sound in air is 340 m/s. What is the wavelength of a sound heard in the air with this frequency? A light bulb with a potential difference of 120 V across it carries a current of 1.5 A. Which of the following is the power consumption of the light bulb? Electromagnetic waves with low frequencies have been used for long-distance underwater communication. These waves most likely belong to which of the following parts of the electromagnetic spectrum? An electric fan has a power output of 60 W. How much work is done if the fan operates for 120 s? The diagram below represents a block sliding across a table at a constant speed. All forces are shown except the frictional force. What is the magnitude of the frictional force on the block? During a thunderstorm, which of the following travels at a speed closest to 3.00 x 108 m/s? An athlete is training for a race by performing timed trials of sprints up a staircase. Which set of variables most directly affects the athlete’s power? An appliance draws 4 A of current when connected to 120 V. What is the resistance of the appliance? Which of the following statements best explains how heat flows by conduction? Which of the following graphs best represents how the force between two identical electric charges varies as the charges move away from each other? Which of the following properties makes a light wave different from all mechanical waves?

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 performs an experiment to determine the relationships among voltage, current, and resistance. The student’s procedure includes the following steps:

• Connect a 3.0 V battery to a 42-ohm resistor.
• Measure the current using an ammeter and record the value.
• Replace the 42-ohm resistor with a 54-ohm resistor, and then with a 66-ohm resistor, measuring and recording the current for each resistor.

The table below shows the data collected. a. Draw a schematic diagram of the student’s original circuit with the 42-ohm resistor. Be sure to label the battery and the resistor.

 b. Describe in words the relationship between current and resistance as voltage is held constant.

 The student will investigate these relationships further using a different experiment.   c. Write a procedure the student could use to test the relationships among voltage, current, and resistance if the only materials available for use are three 3.0 V batteries, one 30-ohm resistor, wire, and an ammeter.

 d. Make a data table similar to the Student’s Data table above to show the expected current measurements for your procedure from part (c).

Refer to the following information for the next four questions. A 70 kg person is swinging on a swing set, as shown in the diagram below. Positions X and Z represent the highest points of the person’s motion, and position Y represents the lowest point of the person’s motion. a. At which position does the person have maximum kinetic energy? Explain your answer.

 b. Neglecting friction, describe the energy conversion as the person travels from position X to position Y.

 c. The person is 1.0 m above the ground at position Y and 1.5 m above the ground at position Z. Neglecting friction, calculate the change in gravitational potential energy as the person swings from position Y to position Z. Show your calculations and include units in your answer.

 d. Neglecting friction, calculate the speed of the person at position Y. Show your calculations and include units in your answer. Related Documents