Physics Multiple Choice Questions
A 0.2-kg. superball is dropped from the window of a building. It strikes the sidewalk below at 30 m/s and rebounds up at 20 m/s. The impulse on the ball during the collision is: a. 10 N × s upward b. 10 N × s downward c. 2.0 N × s upward d. 2.0 N × s downward e. 9.8 m/s² downward
A
A 2-kg mass and a 4-kg mass on a horizontal frictionless surface are connected by string A having negligible mass. The 2-kg mass is on the right, and is pulled horizontally to the right by a second string B (also having negligible mass), resulting in a constant acceleration of 12 m/s². What is the magnitude of the tension in string B on the 2-kg mass? a. 72 N b. 48 N c. 24 N d. 6 N e. 3 N
A
A ball with a momentum of 4.0 kg × m/s hits a wall and bounces straight back without losing any kinetic energy. What is the change in the ball's momentum? a. -8.0 kg × m/s b. -4.0 kg × m/s c. 0.0 kg × m/s d. 4.0 kg × m/s e. 8.0 kg × m/s
A
A force: a. is a push or pull exerted on an object from the interaction of that object with its environment b. requires contact between 2 objects c. always causes motion d. a and b e. a and c
A
Choose all answer combinations that complete the following statement: __ is always in the direction __. a. acceleration/of the net force b. displacement/of the net force c. displacement/of the acceleration d. acceleration/opposite to the frictional force
A
For a pipe with a steady flow: If the flow speed decreases and the pipe is level, the fluid pressure must __. a. increase b. decrease c. stay the same d. equal zero e. need more information (explain)
A
For a pipe with a steady flow: If the pipe gains elevation and its cross-sectional area decreases, the fluid velocity must __. a. increase b. decrease c. stay the same d. equal zero e. need more information (explain)
A
For a pipe with a steady flow: If the pipe is level and its cross-sectional area decreases, the fluid velocity must __. a. increase b. decrease c. stay the same d. equal zero e. need more information (explain)
A
If 2 objects of equal mass are accelerated from rest to the same speed in different time intervals, the impulse a. is the same for both b. is greater for the object that has a greater acceleration c. depends on factors not stated
A
If a 25-N crate is on an incline that is 25° above the horizontal with a coefficient of friction of 0.30, the magnitude of the force needed to keep it in place (parallel to the incline) would be: a. 4.1 N b. 4.6 N c. 8.9 N d. 11 N e. 23 N
A
When an increase in speed doubles the kinetic energy of an object, its momentum a. increases, but less than doubles b. doubles c. more than doubles d. depends on factors not stated
A
When you drop a ball, it accelerates downward at 9.8 m/s². If instead you throw it horizontally, then its acceleration immediately after leaving your hand, assuming no air resistance, is a. 9.8 m/s² b. more than 9.8 m/s² c. less than 9.8 m/s² d. Cannot say, unless the speed of throw is given
A
Which of the following quantities is not a vector? a. mass b. displacement c. weight d. acceleration e. force
A
Choose all answer combinations that complete the following statement: __ is always in the direction __. a. velocity/of motion b. acceleration/of the net force c. acceleration/of the velocity d. the force of friction/opposite to the velocity e. displacement of the acceleration
A, B, D
In a rush to get to school in the morning, you leave your coffee cup sitting on top of the car. The cup slides towards the rear of the car. According to Newton's 1st law, which one or more of the following statements could describe the motion of the car? (choose all that apply) a. the car was at rest, but suddenly accelerates forward b. the car was already moving forward, then accelerates in the direction of motion c. the car was backing down the driveway, then suddenly brakes for someone walking their dog d. the car was already moving forward, then brakes for a stop sign e. the car was at rest, but suddenly accelerates in reverse
A, B, D
A 2-kg mass and a 4-kg mass on a horizontal frictionless surface are connected by string A having negligible mass. The 2-kg mass is on the right, and is pulled horizontally to the right by a second string B (also having negligible mass), resulting in a constant acceleration of 12 m/s². What is the magnitude of the tension in string A on the 4-kg mass? a. 72 N b. 48 N c. 24 N d. 6 N e. 3 N
B
A kick delivers a force of 270 N to a soccer ball. The force that the ball exerts on the foot during this event is: a. less than 270 N because the ball has a smaller mass b. equal to 270 N c. more than 270 N because the person kicking the ball has a larger mass d. there is no force from the ball on the foot e. Need more information, like the mass and acceleration of the ball
B
According to Newton's 3rd Law, every action has an equal and opposite reaction. The reaction force does not cancel out the action force because: a. they are in the same direction b. they act on different objects c. the reaction force only exists after the action force stops d. the action force is slightly larger e. the reaction force is slightly larger
B
An object is moving with a constant velocity. All but one of the following statements could be true. Which one cannot be true? a. no forces act on the object b. a single force acts on the object c. two forces act simultaneously on the object d. three forces act simultaneously on the object e. there is a frictional force and at least one other force acting on the object
B
Another name for momentum is: a. energy in motion b. inertia in motion c. force in motion
B
Mass differs from weight in that: a. all objects have weight but some lack mass b. weight is a force and mass is not c. the mass of an object is always more than its weight d. mass can be expressed only in the metric system e. there is no difference
B
The block shown (refer ch. 4 test, #5) moves with constant velocity on a horizontal surface. Two of the forces acting on it are shown. A frictional force exerted by the surface is the only other horizontal force on the block. The frictional force is: a. 0 b. 2 N, to the left c. 2 N, to the right d. slightly more than 2 N, to the left e. slightly less than 2 N, to the left
B
The equation of continuity for a fluid flow can be derived from the conservation of: a. energy b. mass c. momentum d. force e. pressure
B
The term "mass" refers to the same physical concept as a. weight b. inertia c. force d. acceleration e. volume
B
Which vectors shown in the figure (refer ch. 3 test pt. 1, #3) have vertical components that are equal? a. d₁ and d₂ b. d₁ and d₃ c. d₂ and d₅ d. d₄ and d₅
B
A 2-kg mass and a 4-kg mass on a horizontal frictionless surface are connected by string A having negligible mass. The 2-kg mass is on the right, and is pulled horizontally to the right by a second string B (also having negligible mass), resulting in a constant acceleration of 12 m/s². What is the magnitude of the net force on the 2-kg mass? a. 72 N b. 48 N c. 24 N d. 6 N e. 3 N
C
A 57.1-g egg is released from rest and falls toward earth. After 0.756 s, the magnitude of its momentum is: a. zero b. 0.212 kg × m/s c. 0.423 kg × m/s d. 0.847 kg × m/s e. 7.42 kg × m/s
C
A Newton is the force: a. of gravity on a 1-kg object b. of gravity on a 1-g object c. that gives a 1-kg object an acceleration of 1 m/s² d. that gives a 1-kg object an acceleration of 9.81 m/s²
C
A force of 1 N is: a. 1 kg/s b. 1 kg × m/s c. 1 kg × m/s² d. 1 kg × m²/s e. 1 kg × m²/s²
C
A heavy wooden block is dragged by a force F along a rough steel plate. The force is always of the same magnitude and always oriented parallel to the surface. In one setup, the block is pulled along a horizontal flat surface, and in another it is pulled up an incline. The normal force up the incline, as compared to the normal force along the horizontal surface is: a. Equal to the weight in both cases b. Greater c. Always less d. Less for some angles of the incline and greater for others e. Depends on the magnitude of force F
C
An elastic collision is one in which: a. momentum is not conserved but kinetic energy is b. momentum is conserved but kinetic energy is not c. both momentum and kinetic energy are conserved
C
As the mass of an object increases, what other property of the object increases as well? a. acceleration b. force c. inertia d. velocity e. none of these
C
Based on the books in question 13 (refer ch. 4 review, #13), the force of the physics book on the chemistry book is: a. 0 b. 5 N up c. 9 N up d. 19 N up e. doesn't matter because everyone knows the real force is in the top book
C
For a pipe with a steady flow: If the pipe is level and its cross-sectional area decreases, the flow rate must __. a. increase b. decrease c. stay the same d. equal zero e. need more information (explain)
C
For a pipe with a steady flow: If the pipe is level and its cross-sectional area is constant, the difference in fluid pressure between one end of the pipe and the other must __. a. increase b. decrease c. stay the same d. equal zero e. need more information (explain)
C
How many vectors shown in the figure (refer ch. 3 test pt. 1, #2) have nonzero horizontal components? a. 2 b. 3 c. 4 d. 5
C
If a force is exerted on an object, which statement is true? a. A large force always produces a large change in the object's momentum b. A large force produces a large change in the object's momentum only if the force is applied over a very short time interval. c. A small force applied over a long time interval can produce a large change in the object's momentum.
C
If the total momentum of a system is changing: a. objects of the system must be exerting forces on each other. b. the system must be under the influence of gravity. c. a net external force must be acting on the system. d. none of the above.
C
The SI base unit of pressure is a pascal (Pa). A pressure of 1 PA is equal to: a. 1 kg × m/s² b. 1 kg/s² c. 1 kg/(m × s²) d. 1 kg/(m² × s²) e. 1 kg/m²
C
The coefficient of friction: a. is in the direction of the frictional force b. is in the direction of the normal force c. is the ratio of frictional force to normal force d. can have units of Newtons e. is none of the above
C
The free-body diagram on the right (refer ch. 4 makeup test, #4) shows all the forces acting on an object supported by a stationary horizontal surface, where the length of each vector is proportional to its magnitude. Which statement below is correct? a. The object must be moving to the left, since the net force acts in that direction. b. The object must be accelerating to the right, as indicated by the force of friction in the opposite direction. c. The object must be moving to the right, as indicated by the force of friction in the opposite direction. d. The diagram is drawn incorrectly because there must be another force for the frictional force to oppose. e. None of these statements are correct.
C
The inertia of an object tends to cause the object to: a. speed up b. slow down c. resist any change in its motion d. fall toward Earth e. come to rest because of friction
C
Three identical blocks are being pulled or pushed across the same surface by a force F, as shown in the drawings (refer ch. 4 makeup test, #2). The force F in each case has the same magnitude. Rank the kinetic frictional forces that act on the blocks in ascending order (smaller first) a. B, C, A b. C, A, B c. B, A, C d. C, B, A e. A, C, B
C
When comparing the momentum of two moving objects, which of the following is correct? a. The object with the higher velocity will have less momentum if the masses are equal. b. The more massive object will have less momentum if its velocity is greater. c. The less massive object will have less momentum if the velocities are the same. d. The more massive object will have less momentum if the velocities are the same.
C
Which of the curves on the graph best represents the horizontal component vx of the velocity versus time t for a projectile fired at an angle 45° above the horizontal? a. OC b. DE c. AB d. AE e. AF
C
Which equation(s) expresses the law of conservation of momentum? a. p = mv b. ΔKE = 0 c. pf = pi d. m₁v₁, i + m₂v₂, i = (m₁ + m₂)Vf e. FΔt = Δp, where the impulse is nonzero
C, D
You stand on a scale on the floor of an elevator. Of the following, which 2 answers would give the same reading on the scale? a. moves upward with increasing speed b. moves upward with decreasing speed c. remains stationary d. moves downward with increasing speed e. moves downward at constant speed
C, E
A 1.0-kg ball hits the floor at 2.0 m/s and rebounds with a speed of 1.5 m/s. The change in momentum of the ball is: a. zero b. 0.5 kg × m/s away from the floor c. 0.5 kg × m/s toward the floor d. 3.5 kg × m/s away from the floor e. 3.5 kg × m/s toward the floor
D
A 25-N crate is held at rest on a frictionless incline by a force that is parallel to the incline. If the incline is 25° above the horizontal, the magnitude of the applied force is: a. 4.1 N b. 4.6 N c. 8.9 N d. 11 N e. 23 N
D
Acceleration is always in the direction: a. of the displacement b. of the initial velocity c. of the final velocity d. of the net force e. opposite to the frictional force
D
Consider a ball rolling down an inclined plane. The normal force on the ball (the force perpendicular to the plane): a. is mg b. is greater than mg, always c. may be greater or less than mg. d. is less than mg, always.
D
Impulse has the same dimensions as: a. force b. power c. energy d. momentum e. work
D
Three books rest on a table. The weight of each book is indicated (refer ch. 4 review, #13). The net force acting on the chemistry book is: a. 4 N down b. 5 N up c. 9 N down d. 0 e. None of these
D
Two objects A and B have equal kinetic energies. The mass of A is 9 times that of B. The ratio of the momentum of A to that of B is: a. 1:9 b. 1:3 c. 1:1 d. 3:1 e. 9:1
D
When a certain force is applied to a 1-kg object, its acceleration is 5 m/s². When the same force is applied to another object its acceleration is 1/5 as much. The mass of this object is: a. 0.2 kg b. 0.5 kg c. 1.0 kg d. 5.0 kg e. 10 kg
D
Which of the curves on the graph (refer ch. 3 test pt. 1, #4) best represents the vertical component vy of the velocity versus time t for a projectile fired at an angle 45° above the horizontal? a. OC b. DE c. AB d. AE e. AF
D
The coefficient of kinetic friction: a. is in the direction of the frictional force b. is in the direction of the normal force c. is the ratio of force to area d. can have units of Newtons e. is none of the above
E
The diagram shows a pipe of uniform cross section in which water is flowing (refer ch. 8 test, #7). The directions of flow and the volume flow rates (in cm³/s) are shown for various portions of the pipe. The flow rate and direction in the portion marked A are: a. 3 cm³/s down b. 7 cm³/s up c. 9 cm³/s down d. 11 cm³/s up e. 15 cm³/s down
E
The figure shows three containers filled to the same height with the same fluid (refer ch. 8 test, #4). Rank them according to the pressure exerted by the water on the bottom of the container, least to greatest. a. A, B, C b. B, C, A c. C, A, B d. C, B, A e. All three containers have the same pressure at the bottom.
E
When a violin is played, the bow causes the strings to vibrate. The vibrating string causes the body to vibrate and thus sound emanates from the body of the instrument. Consider the following statements: i. Light waves are like the waves on the string because both are transverse waves. ii. Light waves are like the waves on the string because light waves can only propagate in one dimension, along a single line. iii. Light waves are like the sound waves because light waves propagate in three dimensions. Which statement(s) are correct? a. i only b. ii only c. iii only d. i and ii e. i and iii
E
Can the kinetic energy of an object ever be negative? Yes or no.
No
Can the speed of an object change if the net work done on it is zero? Yes or no.
No
If an object's velocity is negative and acceleration is positive, is the object speeding up, slowing down, or traveling at constant speed?
Slowing down
The work done by the force of friction is always negative. True or false.
True
The critical angle is a special angle in that light that is incident at an angle (less/greater) than the critical angle--as measured with respect to the surface normal--will completely reflect back. What direction must the light be traveling for this to occur: air to plastic or plastic to air?
greater, plastic to air
