review questions PHYS

A ball is swung around in a circle. The force that provides the centripetal force to keep it moving in a circle is A. tension B. gravity C. the normal force D. friction

A

A ball on a string is being swung counterclockwise in a circle. If the string breaks while the ball is at the top of the circle the ball will A. continue moving to the left B. continue moving to the right C. fall straight to the ground D. continue moving in a circle

A

A completely submerged object always displaces its own A. volume of liquid B. weight of fluid C. density of fluid D. all of the above E. none of the above

A

A light person and a heavy person jump from an airplane at the same time and open their same-size parachute at the same time. Which person will reach their terminal velocity first? A. the light person B. the heavy person C. the will reach terminal velocity at the same time

A

A mother and her young child are playing in a swimming pool. Which experiences the greater buoyant force when submerged in the water? A. the mother B. the child C. they experience the same buoyant force

A

A projectile is fired from ground level into the air at an angle of 50 degrees above ground level and hits a target downrange. It will also hit the target if fired at an angle of A. 40 degrees B. 45 degrees C. 55 degrees D. 60 degrees

A

A sack of potatoes are weighing 200 N falls fro an airplane. As its velocity increases, air resistance also increases. When air resistance equals 200 N, the sack's acceleration becomes A. 0 m/s B. 5 m/s C. 10 m/s D. greater than 10 m/s

A

A scale from which a rock is suspended reads 5 N when the rock is our of water snd 3 N when the rock is submerged. Buoyant force on the rock is A. 2 N B. 3 N C.4 N D. 5 N

A

A super ball is dropped and bounces back with the same speed it hit the floor. This type of collision is an A. elastic collision B. inelastic collision

A

At the end of her routine, a figure skater spins with her arms fully extended. She then pulls her arms in very close to her body, and as a result, spins faster. What can be said about the moment of inertia of the skater before and after this action? A. her moment of inertia decreases as she brings her arms in B. her moment of inertia increases as she brings her arms in C. her moment of inertia remains constant as she brings her arms i

A

During an eclipse of the sun, the moon is in new phase. When this occurs, the high ocean tides on earth are A> extra high B. extra low C. not significantly different

A

Impulse is defined as force multiplied by time. This means impulse is ____ proportional to force and ____ proportional to time. A. directly/directly B. directly/inversely C.inversely/directly D.inversely/inversely

A

Padded dashboards in cars are safer in an accident than non-padded ones because passengers hitting the dashboard encounter A. lengthened time of contact B. shorter time of contact C. decreased impulse D. decreased momentum E. both a lengthened time of contact and a smaller change in momentum

A

Pumise is a volcanic rock ghat floats, which means its density is A. less than the density of water B. equal to the density of water C. more than the density of water

A

Suppose you walk slowly up a staircase. Which of the following is true if you had run quickly up the staircase instead? A. running up the stairs requires more power B. you do more work when you run up the stairs C. Your potential energy will increase more if you run up the stairs because you have more kinetic energy D. all of the above are true

A

The earth is closest to the sun in January and farthest in July. How does the speed it moves in its orbit in January compare to July? A. The Earth moves fastest in January B. the earth moves slowest in january C. the speed with which the earth moves is constant all year

A

The language of science is A. mathematics B. Latin C. Chinese D. Arabic E. english

A

The tendency of a unmoving object to remain in unchanging motion in the absence of an unbalanced force is called A. inertia B. free fall C. acceleration D. impulse

A

When you toss a projectile horizontally, it curves as it falls. It will be an Earth satellite if the curve it makes A. matches the curvature of the earth's surface B. results in a straight line C. spirals out indefinitely D. none of the above-an objects must be launched straight up to become a satellite

A

You are riding on a train with your backpack in a luggage rack above you. As a train suddenly _____, your backpack appears to slide backwards. A. speeds up B. slows down C. turns left D. tuns right E. the change in speed of the train will not effect the motion of the backpack

A

A 1-kg chunk of putty moving at 1 m/s collides with and sticks to a 5-kg bowling ball initially at rest. The bowling ball and putty then move with a momentum of A. 0 kg m/s B. 1 kg m/s C. 2 kg m/s D. 5 kg m/s

B

A book sits at rest on a table. The forces acting on it are its weight and a normal force, as shown in the figure. These forces are equal in strength but opposite in direction. Are W and N an action-reaction force pair? A. Yes B No

B

A brick slides across a horizontal rough surface and eventually comes to a stop. What happened to the kinetic energy of the brick? A. nothing; it is still in the brick but is ow called potential gravity B. it was converted to other energy forms, mostly thermal energy C. it was converted to a potential energy of friction D. it was simply destroyed i the process of stopping

B

A bullet fired horizontally over level ground hits the ground in 0.5 seconds. If it had been fired with twice the speed i would have it the ground in A. less than 0.5 s B. 0.5 s C. more than 0.5 s

B

A cart changes its speed from 90 m/s to 100 m/s in 1o seconds. During this interval its acceleration is A. zero B. 1 m/s C. 9 m/s D. 19 m/s

B

A force of gravity pulls downward on a book on a table. What force prevents the book from accelerating downward? A. friction B. a normal force C. tension D. there is not a force balancing gravity

B

A tennis racket hits a tennis ball with a 200 N force. The tennis ball hits the racket with a force A. less than 200 N B. equal to 200 N C. more than 200 N D. the tennis ball does not exert a force on the racket because it experience a longer acceleration

B

A torque acting on an object tends to produce A.equilibrium B. rotation C. linear motion D. velocity E. a center of gravity

B

As water drops fall at a steady rate fro a leaking faucet, they A. get closer together B. get farther apart C. remain a relatively fixed distance form one another

B

Nellie tosses a ball upward at an angle. Assuming no air resistance, which component of velocity changes with time? A. the horizontal component B. the vertical component C. both of these D. neither of these

B

The buoyant force acting on a 10-ton ship floating in the ocean is A. less than 10 tons B. 10 tons C. more than 10 tons D. depends on density of sea water

B

Two identical freight cars roll without friction toward each other on a level track. They collide, stick together, and roll away in the direction of A. the slower car B. the faster car C. neither, for they stop

B

Water pressure on a submerged object is greatest against its A. top B. bottom C. sides D. same against all surfaces E. none of the above

B

When a washing machine goes through its "spin" cycle, the water is extracted from the clothes due to A. a centripetal force B. a centrifugal force C. a magnetic force D. a normal force

B

When you walk, you push on the floor to the left and the floor A. also pushes on you to the left B. pushes you to the right C. both of these simultaneously D. cannot push on you

B

Which horse moves faster on a carousel? A. one near inner rail B. one near outer rail C. both move at the same speed

B

You toss a ball straight up in the air. At the highest point, the ball's A. velocity and acceleration are both zero B. velocity is zero but its acceleration is not zero C. velocity is not zero but the acceleration is zero D. velocity is and acceleration are both not zero

B

A green car and a yellow car begin accelerating from rest at the same time. The green car i more massive than the yellow car. The net accelerating force exerted on each car is identical. After 3 seconds, which car has the most momentum? A. the green car B. the yellow car C. the cars have the same momentum

C

A player hits a ball with a bat. If action is the force of the bat against the ball, the reaction is the A.air resistance on the ball B. weight of the ball C. force that the ball exerts on the bat D. grip of the player's hand against the ball E. weight of the bat

C

A same-size iron ball and wooden ball are dropped simultaneously from a tower and reach the ground at the same time. The iron ball had a greater A. speed B. acceleration C. momentum D. all of the above E. none of the above

C

A weightless astronaut in an orbiting satellite is A. shielded from Earth's gravitational field B. beyond the pull of gravity C. in a constant state of free-fall around the earth D. none of the above

C

An egg rests at the bottom of a bowl filled with fresh water. When salt is slowly added to the water the egg rises and floats, from which we conclude A. salt water is denser than fresh water B. salt water is denser than an egg C. both of the above are true D. neither of the above are true

C

Conservation of Momentum is a direct consequence of A. Newton's first law of motion B. newton's second law of motion C. newton's third law of motion

C

If the Sun collapsed to a black hole, Earth's gravitational attraction to it would be A. more B. less C. the same

C

If you are accelerating up in an elevator, your apparent weight is A. less than your weight when standing still B. the same as your weight when standing still C. ore than your weight when standing still

C

Making a simplified sketch of an object with arrows representing the forces on the object is an example of using a ________ to explain its motion. A. theory B.graph C. model D. law E. hypothesis

C

No work is done by gravity on a bowling ball that rolls along a bowling alley because A. no force acts on the ball B. little distance is covered by the ball C. the force on the ball is at right angles to the ball's motion D. the ball's speed remains constant

C

On each given day and location, tides rise and fall at A. about the same time B. exactly the same time C. different times D. ever increasing rates daily

C

Sam pushes Alex on a sled across a flat stretch of snow. Ignoring any friction on the sled, if Sam pushes with a force that is three times as much, the acceleration Alex experiences will be A. 1/3 as much B. the same C. three times as much D. nine times as much

C

Suppose a disk, a solid sphere, and a ring all have the same mass and begin rolling down a hill together. Which reaches the bottom last? A. disk B. sphere C. ring D. all reach the bottom at the same time

C

Which of the following has a net force acting on it? A. a car at rest B. a car moving up a steep incline at a constant velocity C. A car rounding a curve at a constant speed D. A car moving at a constant velocity non a level road E. none of the above

C

Which of the following has a net force acting on it? A. a car at rest B. a car moving up a steep incline at a constant velocity C. a car rounding a curve at a constant velocity D. a car moving at a constant velocity on a level road E. none of the above

C

A ball is rolling down a bowling alley. The force needed to keep this ball rolling is A. due to gravity B. an inertial force C. a slight breeze D. none of these

D

A ball is thrown up with a speed of 20 m/s. What is its speed after 4 seconds? A. 0 m/s B. 5 m/s C. 10 m/s D. 20 m/s E. 80 m/s

D

A bicycle that travels four times as fast as another when braking to a stop will skid a. twice as far B. four ties as far C. eight times as far D. sixteen times as far E. depends on the mass of the bike

D

A child swinging on a swing has their maximum kinetic energy at A. the top B. a quarter of the way down C. halfway down D. the bottom

D

An apple falls from a tree and hits the round 2 s below with a speed of A. 5 m/s B. 10 m/s C. 15 m/s D. 20 m/s

D

At highest point in its trajectory, a projectile has a velocity that is ____ and an acceleration that is ____. A. zero/zero B. zero/not zero C. not zero.zero D. not zero/not zero

D

The famous Leaning Tower of Pisa doesn't topple over because its center of gravity is A. relatively low for such a tall building B. stabilized by its structure C. displaced from its center D. above a place of support E. in the same place as its center of mass

D

When a falling object has reached its terminal velocity, its acceleration is A. less than g, but not zero B. g C. greater than g D. zero

D

Which of the following is not a scientific hypothesis? A. adding heat to water will raise its temp B. A magnet will pick up a copper penny C. the far side of the moon has more crater than the side facing earth D. galileo was the greatest scientist in history E. all of the above scientific hypothesis

D

Imagine you are standing on the surface of a shrinking planet. If it shrinks to half its original diameter with no change in mass, on the shrunken surface you'd weigh A. 1/4 as much B. 1/2 s much C. the same D. 2 times as much E. 4 times as much

E