# Physical Setting 25 January 2007

Physical Setting 25 January 2007 Questions Answer Keys

The University of the State of New York
Regents High School Examination
Physical Setting
Physics
Thursday, January 25, 2007 — 1:15 to 4:15 p.m., only

Directions (1–30): For each statement or question, write on the separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question.

1. Which is a vector quantity?

• (1) electric charge
• (2) electric field strength
• (3) electric potential difference
• (4) electric resistance

Note that question 2 has only three choices.

2. A 6.0-newton force and an 8.0-newton force act concurrently on a point. As the angle between these forces increases from 0° to 90°, the magnitude of their resultant

• (1) decreases
• (2) increases
• (3) remains the same

3. A car increases its speed from 9.6 meters per second to 11.2 meters per second in 4.0 seconds. The average acceleration of the car during this 4.0-second interval is

• (1) 0.40 m/s2
• (2) 2.4 m/s2
• (3) 2.8 m/s2
• (4) 5.2 m/s2

4. What is the speed of a 2.5-kilogram mass after it has fallen freely from rest through a distance of 12 meters?

• (1) 4.8 m/s
• (2) 15 m/s
• (3) 30. m/s
• (4) 43 m/s

5. A machine launches a tennis ball at an angle of 25° above the horizontal at a speed of 14 meters per second. The ball returns to level ground. Which combination of changes must produce an increase in time of flight of a second launch?

• (1) decrease the launch angle and decrease the ball’s initial speed
• (2) decrease the launch angle and increase the ball’s initial speed
• (3) increase the launch angle and decrease the ball’s initial speed
• (4) increase the launch angle and increase the ball’s initial speed

6. A ball attached to a string is moved at constant speed in a horizontal circular path. A target is located near the path of the ball as shown in the diagram.

At which point along the ball’s path should the string be released, if the ball is to hit the target?

• (1) A
• (2) B
• (3) C
• (4) D

7. A plane flying horizontally above Earth’s surface at 100. meters per second drops a crate. The crate strikes the ground 30.0 seconds later. What is the magnitude of the horizontal component of the crate’s velocity just before it strikes the ground? [Neglect friction.]

• (1) 0 m/s
• (2) 100. m/s
• (3) 294 m/s
• (4) 394 m/s

8. A woman with horizontal velocity v1 jumps off a dock into a stationary boat. After landing in the boat, the woman and the boat move with velocity v2. Compared to velocity v1, velocity v2 has

• (1) the same magnitude and the same direction
• (2) the same magnitude and opposite direction
• (3) smaller magnitude and the same direction
• (4) larger magnitude and the same direction

9. Which object has the greatest inertia?

• (1) a 5.0-kg object moving at a speed of 5.0 m/s
• (2) a 10.-kg object moving at a speed of 3.0 m/s
• (3) a 15-kg object moving at a speed of 1.0 m/s
• (4) a 20.-kg object at rest

10. As an astronaut travels from the surface of Earth to a position that is four times as far away from the center of Earth, the astronaut’s

• (1) mass decreases
• (2) mass remains the same
• (3) weight increases
• (4) weight remains the same

11. A 0.15-kilogram baseball moving at 20. meters per second is stopped by a catcher in 0.010 second. The average force stopping the ball is

• (1) 3.0 × 10–2 N
• (2) 3.0 × 100 N
• (3) 3.0 × 101 N
• (4) 3.0 × 102 N

12. A spring with a spring constant of 80. newtons per meter is displaced 0.30 meter from its equilibrium position. The potential energy stored in the spring is

• (1) 3.6 J
• (2) 7.2 J
• (3) 12 J
• (4) 24 J

13. The work done in accelerating an object along a frictionless horizontal surface is equal to the change in the object’s

• (1) momentum
• (2) velocity
• (3) potential energy
• (4) kinetic energy

14. As a block slides across a table, its speed decreases while its temperature increases. Which two changes occur in the block’s energy as it slides?

• (1) a decrease in kinetic energy and an increase in internal energy
• (2) an increase in kinetic energy and a decrease in internal energy
• (3) a decrease in both kinetic energy and internal energy
• (4) an increase in both kinetic energy and internal energy

15. If 60. joules of work is required to move 5.0 coulombs of charge between two points in an electric field, what is the potential difference between these points?

• (1) 5.0 V
• (2) 12 V
• (3) 60. V
• (4) 300 V

16. Which statement best describes a proton that is being accelerated?

• (1) It produces electromagnetic radiation.
• (2) The magnitude of its charge increases.
• (3) It absorbs a neutron to become an electron.
• (4) It is attracted to other protons.

17. The diagram below represents a simple circuit consisting of a variable resistor, a battery, an ammeter, and a voltmeter.

What is the effect of increasing the resistance of the variable resistor from 1000 Ω to 10000 Ω? [Assume constant temperature.]

• (1) The ammeter reading decreases.
• (2) The ammeter reading increases.
• (3) The voltmeter reading decreases.
• (4) The voltmeter reading increases.

18. If the distance separating an electron and a proton is halved, the magnitude of the electrostatic force between these charged particles will

• (1) unchanged
• (2) doubled
• (3) quartered

19. Two similar metal spheres, A and B, have charges of +2.0 × 10–6 coulomb and +1.0 × 10–6 coulomb, respectively, as shown in the diagram below.

The magnitude of the electrostatic force on A due to B is 2.4 newtons. What is the magnitude of the electrostatic force on B due to A?

• (1) 1.2 N
• (2) 2.4 N
• (3) 4.8 N
• (4) 9.6 N

20. In the diagram below, P is a point near a negatively charged sphere.

# Θ .P

Which vector best represents the direction of the electric field at point P?

Note that question 21 has only three choices.

21. If the amplitude of a wave traveling in a rope is doubled, the speed of the wave in the rope will

• (1) decrease
• (2) increase
• (3) remain the same

22. Two waves having the same amplitude and frequency are traveling in the same medium. Maximum destructive interference will occur when the phase difference between the waves is

• (1) 0°
• (2) 90°
• (3) 180°
• (4) 270°

23. What is the speed of a radio wave in a vacuum?

• (1) 0 m/s
• (2) 3.31 × 102 m/s
• (3) 1.13 × 103 m/s
• (4) 3.00 × 108 m/s

24. A ringing bell is located in a chamber. When the air is removed from the chamber, why can the bell be seen vibrating but not be heard?

• (1) Light waves can travel through a vacuum, but sound waves cannot.
• (2) Sound waves have greater amplitude than light waves.
• (3) Light waves travel slower than sound waves.
• (4) Sound waves have higher frequency than light waves.

25. As a transverse wave travels through a medium, the individual particles of the medium move

• (1) perpendicular to the direction of wave travel
• (2) parallel to the direction of wave travel
• (3) in circles
• (4) in ellipses

26. A straight glass rod appears to bend when placed in a beaker of water, as shown in the diagram below.

What is the best explanation for this phenomenon?

• (1) The water is warmer than the air.
• (2) Light travels faster in water than in air.
• (3) Light is reflected at the air-water interface.
• (4) Light is refracted as it crosses the air-water interface.

27. What happens to the speed and frequency of a light ray when it passes from air into water?

• (1) The speed decreases and the frequency increases.
• (2) The speed decreases and the frequency remains the same.
• (3) The speed increases and the frequency increases.
• (4) The speed increases and the frequency remains the same.

28. Parallel wave fronts incident on an opening in a barrier are diffracted. For which combination of wavelength and size of opening will diffraction effects be greatest?

• (1) short wavelength and narrow opening
• (2) short wavelength and wide opening
• (3) long wavelength and narrow opening
• (4) long wavelength and wide opening

29. Which wave phenomenon occurs when vibrations in one object cause vibrations in a second object?

• (1) reflection
• (2) resonance
• (3) intensity
• (4) tuning

30. A photon having an energy of 9.40 electronvolts strikes a hydrogen atom in the ground state. Why is the photon not absorbed by the hydrogen atom?

• (1) The atom’s orbital electron is moving too fast.
• (2) The photon striking the atom is moving too fast.
• (3) The photon’s energy is too small.
• (4) The photon is being repelled by electrostatic force.