Pre-Assessment: Conceptual Physics (PABR) PDF

Help Articles PRE-ASSESSMENT: CONCEPTUAL PHYSICS (PABR) Attempt #2 Status: Passed 1. Newton’s law of universal gravitation is an example of an inverse square law. What is another inverse square law?...

Help Articles PRE-ASSESSMENT: CONCEPTUAL PHYSICS (PABR) Attempt #2 Status: Passed 1. Newton’s law of universal gravitation is an example of an inverse square law. What is another inverse square law? YOUR CORRECT ANSWER ANSWER Coulomb's law Newton's first law of motion Second law of thermodynamics Ampere's law for magnetic field production 2. What happens to the gravitational force when the distance between two objects is halved? YOUR CORRECT ANSWER ANSWER The force quadruples. The force doubles. The force will not be affected. The force halves. 3. What is true about gravitational force? YOUR CORRECT ANSWER ANSWER Gravitational force decreases as the distance between two objects increases. Gravitational force is only felt on Earth. Gravitational force is calculated using the difference in mass between two objects. Gravitational force does not act on astronauts in space. Accessibility Policy Accessibility Settings 4. What would happen to a person’s weight if Earth’s mass was decreased by 10%? YOUR CORRECT ANSWER ANSWER The person’s weight would be reduced by 10%. The person’s weight would be increased by 10%. The person’s weight would remain the same. The person’s weight would be increased by 100%. 5. A car, initially at rest, is moving with a velocity of 30 m/s after 5 s. What is the average acceleration of the car? YOUR CORRECT ANSWER ANSWER 5 m/s2 6 m/s2 25 m/s2 150 m/s2 6. A mass is dropped from rest near the Earth's surface and falls for 5 seconds. There is no air resistance. Which distance does this mass fall? YOUR CORRECT ANSWER ANSWER 50.0 m 122.5 m 155.5 m 250.0 m 7. What is the acceleration of a 5 g nickel dropped down a 25 m well? Accessibility Policy Accessibility Settings  YOUR CORRECT ANSWER ANSWER 0.2 m/s/s 5 m/s/s 9.8 m/s/s 125 m/s/s 8. The slope on a velocity-time graph is –0.5 m/s/s, and the graph starts with an object at a velocity of 10. What is the motion of the object? YOUR CORRECT ANSWER ANSWER Moving in a positive direction with negative acceleration Moving in a negative direction with positive acceleration Moving in a negative direction at a constant speed Moving in a positive direction at a constant speed 9. A 50 kg ice-skater is at rest on the ice. The ice-skater’s friend throws a 5 kg ball to the ice-skater. The ice-skater and the ball then move backward on the ice with a speed of 1 m/s. What was the speed of the ball at the moment just before the skater caught it? YOUR CORRECT ANSWER ANSWER 8 m/s 9 m/s 10 m/s 11 m/s 10. Two vans that appear to be identical collide on an icy road. One was originally at rest. The vans are now stuck together and move at half the initial speed of the van that was moving. What can you conclude about the vans? Accessibility Policy Accessibility Settings  YOUR CORRECT ANSWER ANSWER The vans were of equal mass. The van at rest has half the mass of the van that was moving. The van that was moving has half the mass of the van that was at rest. The van at rest has double the mass of the van that was moving. 11. Two objects with the same mass move toward each other with the same speed and experience an elastic collision. How will their final velocities compare with their initial velocities? YOUR CORRECT ANSWER ANSWER The final velocities will be half of their initial velocities, just in a different direction. The final velocities will be one-fourth of their initial velocities, just in a different direction. The final velocities will be the same as their initial velocities, just in a different direction. The final velocities will be double their initial velocities, just in a different direction. 12. A less massive object is moving in the same direction as a more massive object but with a higher speed. The objects experience an inelastic collision. Which statement describes the speed of the more massive object after the collision? YOUR CORRECT ANSWER ANSWER Its final speed will be higher than its initial speed. Its final speed will be less than its initial speed. Its final speed will be the same as its initial speed. Its final speed will be zero. Accessibility Policy Accessibility Settings 13. A 4 kg object is being pushed with a steady force. As it moves, the object experiences a frictional force of 10 Newtons. The object is slowing down at a rate of 10 m/s2. What is the magnitude of the force pushing on the object? YOUR CORRECT ANSWER ANSWER 20 N 30 N 40 N 50 N 14. A projectile is launched with an initial velocity of 2.8 m/s at an angle of 30° above the ground. There is no air resistance. What is the vertical component of the velocity at the projectile's maximum height? YOUR CORRECT ANSWER ANSWER 0.0 m/s 1.4 m/s 2.8 m/s 4.2 m/s 15. A 32 kg child sits on a 3.5 kg tire swing that is hanging from a tree branch with one rope supporting it. What is the tension in the rope that hangs from the tree branch? YOUR CORRECT ANSWER ANSWER 280 N 310 N 350 N 370 N Accessibility Policy Accessibility Settings 16. A rock is kicked horizontally at a speed of 5.5 m/s off a cliff that is 82.4 m high. How far from the base of the cliff does the rock land? YOUR CORRECT ANSWER ANSWER 16 m 23 m 52 m 92 m 17. A computer weighing 20 N is resting on a desk. What is the force exerted on the computer by the desk? YOUR CORRECT ANSWER ANSWER –20 N –9.8 N 9.8 N 20 N 18. What happens when a person throws a rock in space where there is no gravity? YOUR CORRECT ANSWER ANSWER The person moves backwards. The person follows the rock forward. The person stays motionless. The person turns toward the arm that threw the rock. 19. Which object has the greatest inertia? YOUR CORRECT ANSWER ANSWER A refrigerator Accessibility Policy Accessibility Settings  YOUR CORRECT ANSWER ANSWER A gallon of water A cell phone A laptop 20. Which situation demonstrates Newton’s third law? YOUR CORRECT ANSWER ANSWER A ball bouncing A car slowing down An asteroid traveling through space A car going around a corner 21. A system has 2,400 J of heat added to it, and then 1,600 J of work is done on the system. Given that ΔU = Q – W, what is the change in internal energy of the system? YOUR CORRECT ANSWER ANSWER –4,000 J –800 J +800 J +4,000 J 22. A heat engine operating in a cycle absorbs 100 J from a high-temperature reservoir, does some work, and exhausts heat to a low-temperature reservoir. Which set of values for the work done (W) and the heat exhausted to the low-temperature reservoir (Q) is possible? YOUR CORRECT ANSWER ANSWER W = 30 J, Q = 70 J W = 80 J, Q = 10 J Accessibility Policy Accessibility Settings  YOUR CORRECT ANSWER ANSWER W = 80 J, Q = 30 J W = 100 J, Q = 100 J 23. Which device uses a heat engine? YOUR CORRECT ANSWER ANSWER A diesel truck A wind turbine A battery A fireplace 24. 1.92 × 105 J of heat is added to a 5 kg pot to increase the temperature of the pot by 100°C. Which material is the pot made from? YOUR CORRECT ANSWER ANSWER Aluminum (specific heat of 897 J/(kg K)) Copper (specific heat of 385 J/(kg K)) Iron (specific heat of 450 J/(kg K)) Zinc (specific heat of 388 J/(kg K)) 25. What does the term heat refer to? YOUR CORRECT ANSWER ANSWER A measure of the average kinetic energy in an object Energy contained in an object because of its heat capacity Energy that flows from one body to another because of a temperature difference Amount of energy an object has because it is above absolute zero Accessibility Policy Accessibility Settings 26. Which property of gas is determined by the average kinetic energy of its molecules? YOUR CORRECT ANSWER ANSWER Temperature Volume Pressure Ionization energy 27. Which of the following is an example of an object with potential energy? YOUR CORRECT ANSWER ANSWER Water in a pressurized tank Wind blowing through trees A car traveling down a road A pizza baking in an oven 28. An athlete with a mass of 80 kg has a top running speed of 10 m/s. Frictional forces may be ignored in this problem. How many joules of work must this athlete exert to go from standing still (0 m/s) to top running speed? YOUR CORRECT ANSWER ANSWER 800 J 1,600 J 4,000 J 8,000 J 29. A 20 N force pushes a 5 kg block for 10 m on a horizontal surface. The coefficient of friction between the block and the surface is 0.3. What is the increase in kinetic energy of the block? Accessibility Policy Accessibility Settings  YOUR CORRECT ANSWER ANSWER 53 J 60 J 147 J 200 J 30. What is the relationship between work and power? YOUR CORRECT ANSWER ANSWER Work is applying power over a distance. Work is applying power over time. Power is applying work over time. Power is applying work over a distance. 31. A 0.67 kg toy is tied to the end of a string that is 0.65 m long and is spun around in a circular motion. A force of 5.5 N is exerted on the string to keep the toy moving in a circle. What is the speed of the ball? YOUR CORRECT ANSWER ANSWER 1.9 m/s 2.3 m/s 3.7 m/s 5.3 m/s 32. Which statement describes the direction of acceleration of an object with constant circular motion? YOUR CORRECT ANSWER ANSWER The acceleration is in a direction tangential to the circle. The acceleration is toward the center of the circle. Accessibility Policy Accessibility Settings  YOUR CORRECT ANSWER ANSWER The acceleration is away from the center of the circle. The acceleration is zero. 33. An object is moving on a circular path. In what direction does a centripetal force act? YOUR CORRECT ANSWER ANSWER Along the radius of the circle, away from the center Tangent to the circle, in the direction of motion Along the radius of the circle, toward the center Tangent to the circle, opposite to the direction of motion 34. Which proportion of the current travels through R2 in the following circuit? R1 = 100 Ω, R2 = 300 Ω YOUR CORRECT ANSWER ANSWER 25% 33% 50% 75% Accessibility Policy Accessibility Settings 35. Which combination of resistors describes the given circuit? YOUR CORRECT ANSWER ANSWER R1 is in parallel with R3, and R2 is in parallel with R3. R1 is in series with R3, and R2 is in series with R3. R1 is in series with R2, and R1 + R2 is in parallel with R3. R1 is in parallel with R2, and R1 + R2 is in series with R3. 36. A solar panel generating 310 W of electricity provides an output of 32 V. What is the current provided by the panel? YOUR CORRECT ANSWER ANSWER 0.10 A 9.7 A 278 A 9,920 A 37. A bar magnet is broken into three pieces as illustrated in the following image. Accessibility Policy Accessibility Settings  What is the correct order of the new magnetic poles from left to right (1–6)? YOUR CORRECT ANSWER ANSWER N, S, N, S, N, S N, S, S, N, N, S N, S, S, S, S, N N, N, N, S, S, S 38. A child tried to attach a second train car to the one shown above, but the cars would not stick together. What is the likely explanation for this observation? YOUR CORRECT ANSWER ANSWER The south pole on the second car repelled Magnet 1. The south pole on the second car repelled Magnet 2. The north pole on the second car repelled Magnet 2. Both poles on the second car repelled Magnet 1. 39. Which statement about magnets is correct? YOUR CORRECT ANSWER ANSWER Not all magnets have both a north pole and a south pole. Opposite poles of a magnet repel each other; like poles attract each other. You can isolate a single pole by breaking a magnet in half. The source of magnetic force is the motion of charged particles. Accessibility Policy Accessibility Settings 40. The field lines of a uniform magnetic field are horizontal and point north. What will continue to induce a voltage in a conductor after it is placed in this field? YOUR CORRECT ANSWER ANSWER A long, straight wire that is parallel with a field line and moving north A circular loop of wire that is on a horizontal plane and moving south A long, straight wire that is rotating about its long axis A circular loop of wire that is rotating about an axis perpendicular to the magnetic field 41. A rod that has a positive charge on one end is brought near the end of a neutral rod, which then becomes negatively charged. Which process describes how the neutral rod becomes charged? YOUR CORRECT ANSWER ANSWER Induction Conduction Convection Insulation 42. Two charged plates that are 1 m apart are moved to be 0.5 m apart. What happens to the strength of the electric field? YOUR CORRECT ANSWER ANSWER It increases by a factor of 2. It increases by a factor of 4. It decreases by a factor of 2. It decreases by a factor of 4. Accessibility Policy Accessibility Settings 43. In which direction do the electric field lines between two points with opposite charges run? YOUR CORRECT ANSWER ANSWER In continuous lines from the positive charge to the negative charge In continuous lines from the negative charge to the positive charge In closed loops around each charge individually In closed loops around both charges together 44. The force between two point charges is given by the following equations: kq1 q2 F = 2 r 2 N ⋅ m 9 k = 9.0 × 10 2 C What is the repulsive force between two protons (the charge of a proton is 1.6 × 10–19 C) that are 5.3 × 10–11 m apart? YOUR CORRECT ANSWER ANSWER 1.0 × 1012 N 4.3 × 10–18 N 5.1 × 1011 N 8.2 × 10–8 N 45. What happens when the crest of one wave traveling on a string perfectly meets the crest of a second wave traveling on that same string? YOUR CORRECT ANSWER ANSWER The amplitude of the two waves is increased. The amplitude of the two waves is decreased. Accessibility Policy Accessibility Settings  YOUR CORRECT ANSWER ANSWER The waves bounce off each other and stay erect. The waves bounce off each other and invert. 46. A pendulum-driven clock is running fast. Which aspect of the pendulum can be changed to correct the time? YOUR CORRECT ANSWER ANSWER Length of string Weight of pendulum Mass of pendulum Diameter of pendulum 47. An astronomer observes that the color of light seen from a distant star appears to be blue. What can the astronomer deduce about the motion of this star? YOUR CORRECT ANSWER ANSWER The star is moving toward the astronomer. The star is moving away from the astronomer. The star is moving parallel to the astronomer. The star is not moving at all. 48. What happens to the amplitude of sound waves produced by a siren that approaches a stationary observer? YOUR CORRECT ANSWER ANSWER The amplitude does not change. The amplitude increases. The amplitude decreases. The amplitude doubles. Accessibility Policy Accessibility Settings 49. In which medium is sound carried the fastest? YOUR CORRECT ANSWER ANSWER Solid Liquid Gas Vacuum 50. What happens to the frequency of a sound wave if the wavelength decreases? YOUR CORRECT ANSWER ANSWER It increases. It decreases. It remains the same. It disappears. 51. Which type of radiation consists of two protons and two neutrons bound together? YOUR CORRECT ANSWER ANSWER Alpha Beta Gamma Positron 52. Which type of radiation is released when a neutron breaks down inside the nucleus of an atom? YOUR CORRECT ANSWER ANSWER Beta Alpha Gamma Accessibility Policy Accessibility Settings  YOUR CORRECT ANSWER ANSWER Positron 53. What is the best example of a nuclear fusion process? YOUR CORRECT ANSWER ANSWER 54. Which particles carry the largest amount of energy and travel at high speed when hydrogen atoms fuse together? YOUR CORRECT ANSWER ANSWER Neutrons Protons Electrons Beta 55. An object is 10 cm from a mirror that forms a real image at 25 cm from the surface of the mirror. Which focal length does this object have? YOUR CORRECT ANSWER ANSWER 7.1 cm 12.4 cm 16.7 cm 35.0 cm Accessibility Policy Accessibility Settings 56. n = 1.00 for air n = 1.33 for water What is the angle of refraction if a ray of light passes from air into water at an angle of 30.0°? YOUR CORRECT ANSWER ANSWER 22.1° 30.0° 45.0° 90.0° 57. What is a characteristic of an electromagnetic wave? YOUR CORRECT ANSWER ANSWER The path can be altered by a magnetic field. The electrical and magnetic components oscillate in the same plane. The electrical and magnetic planes of oscillation are perpendicular to each other. The wave path can be altered by an electric field. 58. Which form of electromagnetic radiation has the shortest wavelength? YOUR CORRECT ANSWER ANSWER Visible X-ray Ultraviolet Microwave 59. How does an object’s equivalent energy change if the object’s mass is doubled? YOUR CORRECT ANSWER ANSWER Quadruples Accessibility Policy Accessibility Settings  YOUR CORRECT ANSWER ANSWER Doubles Halves Quarters 60. An electron travels at a speed that is ½ the speed of light. What happens to the apparent mass of the electron? YOUR CORRECT ANSWER ANSWER The mass appears to be less. The mass appears to be more. The mass appears to be double. The mass does not change. Accessibility Policy Accessibility Settings