chap 10
Two identical freight cars roll without friction (one at 1 m/s, the other at 2 m/s) toward one another on a level track. They collide, couple together, and roll away in the direction that a) the slower car was initially going b) the faster car was initially going c) neither of these -- they stop
b
What has the greater mass? a) a king-size pillow b) an automobile battery c) neither - both have the same
b
A bullet is dropped from the top of the Empire State Building while another bullet is fired downward from the same location. Neglecting air resistance, the acceleration of a) the fired bullet is greater b) the dropped bullet is greater c) each bullet is 9.8 meters per second per second
c
A car traveling at 100 km/hr strikes an unfortunate bug and splatters it. The force of impact is a) greater on the bug b) greater on the car c) the same for both
c
A feather and a coin dropped in a vacuum fall with equal A) forces. B) momenta. C) accelerations. D) kinetic energies. E) none of these
c
A heavy truck and a small truck roll down a hill. Neglecting friction, at the bottom of the hill, the heavy truck will have greater A) speed. B) acceleration. C) momentum. D) all of these. E) none of these.
c
A rifle recoils from firing a bullet. The speed of the rifle's recoil is small because the A) force against the rifle is smaller than against the bullet. B) momentum is mainly concentrated in the bullet. C) rifle has much more mass than the bullet. D) momentum of the rifle is smaller.
c
According to Newton, doubling the distance between two interacting objects A) divides by 2 the gravitational force between them. B) multiplies by 2 the gravitatiunal force between them. C) dividesby 4 the gravitational force between them. D) multiplies by 4 the gravitational force between them
c
After rolling halfway down an incline a marble's kinetic energy is A) less than its potential energy. B) greater than its potential energy. C) the same as its potential energy. D) impossible to determine.
c
Arnold Strongman and Suzie Small each pull very hard on opposite ends of a massless rope in a tug-of-war. the greater force on the rope is exerted by a) arnold, of course. b) Suzie, surprisingly. c) both the same, interestingly enough
c
Compared to the force that brings a small car to a stop, the force required to bring a heavy truck traveling at the same speed to a stop A) is less. B) is more. C) may be less and may be more.
c
Disregarding air resistance, objects fall with constant a) velocity b) speed c) acceleration d) distances each successive second
c
If a non-rotating object has no acceleration, then we can say for certain that it is a) at rest b) moving at constant non-zero velocity c) in mechanical equilibrium d) all of these e) none of these
c
If an object falling freely were somehow equipped with an odometer to measure the distance it travels, then the amount of distance it travels each succeeding second would be a) constant b) less and less each second c) greater than the second before d) doubled
c
If an object of constant mass experiences a constant net force, it will have a constant a) velocity b) speed c) acceleration d) position e) more than one of the above
c
If less horizontal force is applied to a sliding object than is needed to maintain a constant velocity a) the object accelerates in the direction of the applied force b) the friction force increases c) the object eventually slides to a stop d) none of the above
c
Neglecting friction, a large block of ice and a small block of ice start sliding down an incline together. The heavier block will get to the bottom a) before the light block b) after the light block c) at the same time as the light block
c
Suppose a particle is being accelerated through space by a 10-N force. Suddenly the particle encounters a second fore of 10N in the opposite direction from the first force. The particle with both forces acting on it a) is brought to a rapid halt b) decelerates gradually to a halt c) continues at the speed it had when it encountered the second force d) theoretically tends to accelerate toward the speed of light e) none of these
c
The attraction of a persons body toward the Earth is called weight. The reaction to this force is a) the person's body pushing against the Earth's surface b) the Earth's surface pushing against the person's body c) the person's body pulling on the Earth. d) none of these
c
The conservation of momentum is most closely related to A) Newton's 1st law. B) Newton's 2nd law. C) Newton's 3rd law.
c
The force on an apple hitting the ground depends upon A) the speed of the apple just before it hits. B) the time of impact with the ground. C) whether or not the apple bounces. D) all of these.
c
The total momentum of a flock of identical birds could be zero only if the birds are a) taking off from the ground b) flying in the same direction c) flying in different directions d) very tired and coming down to rest
c
The two measurements necessary for calculating average speed are a) acceleration and time b) velocity and time c) distance and time d) distance and acceleration e) velocity and distance
c
Two factors that greatly affect air resistance on falling objects are the a) size and mass of the object b) size and weight off the object c) size and speed of the object
c
Two objects, A and B, have the same size and shape, but A is twice as heavy as B. When they are dropped simultaneously from a tower, they reach the ground at the same time, but A has a greater A) speed. B) acceleration. C) momentum. D) all of these. E) none of these.
c
a kilogram is a measure of an object's a) weight b) force c) mass d) size
c
hang from a pair of gym rings and the upward support forces of the rings will always a) each be half your weight b) each be equal to your weight c) add up to equal your weight
c
A ball rolling down an incline has its maximum kinetic energy at A) the top. B) halfway down. C) three-quarters of the way down. D) the bottom.
d
A bullet is fired from a gun. The speed of the bullet will be about the same as the speed of the recoiling gun A) because momentum is conserved. B) because velocity is conserved. C) because both velocity and momentum are conserved. D) if the mass of the bullet equals the mass of the gun. E) none of these.
d
If the sun were twice as massive a) its pull on the Earth would double b) the pull of the Earth on the sun would double c) both of these d) neither of these
c
A feather and a coin will have equal accelerations when falling in a vacuum because a) their velocities are the same b) the force of gravity is the same for each in a vacuum c) the force of gravity does not act in a vacuum d) the ratio of each object's weight to it s mass is the same e) none of these
d
A heavy and a light object released from the same height in a vacuum have equal a) weights b) momenta c) kinetic energies d) accelerations e) none of the above
d
A lightweight feather slides off a table and falls through the air until it reaches the floor. during the time of its fall, it acceleration a) keeps increasing b) keeps decreasing c) never changes d) is sometimes zero
d
A skydiver steps from a helicopter and falls for a few seconds until he reaches his terminal velocity. Thereafter, until he opens his parachute, his acceleration a) is constant b) increases c) decreases d) is zero e) none of these
d
An object may have potential energy because of its A) speed. B) acceleration. C) momentum. D) location. E) none of these
d
In each second of fall, the distance a freely falling object will fall is a) about 5m b) about 10m c) the same, but not 5m or 10m d) increasing e) none of these
d
Strictly speaking, more fuel is consumed by your car if an air conditioner, headlights or even a radio is turned on. This statement is a) totally false b) true only if the car's engine is running fast c) true only if the car's engine is running slowly d) almost always true
d
The force that accelerates a rocket in outer space is exerted on the rocket by the A) rocket's engine. B) rocket's wings. C) atmospheric pressure. D) exhaust gases. E) none of these.
d
When you relax at rest with your left foot on one bathroom scale and your right foot on a similar scale, each of the scales will a) indicate exactly half your weight b) indicate part of your total weight but non necessarily half of it c) indicate different values that will equal your weight when added together d) any of the above may be correct
d
Which has zero acceleration? An object a) at rest b) moving at constant velocity c) in mechanical equilibrium d) all of these e) none of these
d
compared to a 1-kg block of solid iron, a 2-kg block of solid iron has twice as much a) inertia b) mass c) volume d) all of these e) none of these
d
A skydiver falls toward the Earth. The attraction of the Earth on the diver pulls the diver down. What is the reaction to this force? a) air resistance the diver encounters while falling b) water resistance that will soon act upon on the diver c) the attraction to the planets, stars, and every particle in the universe d) all of these e) none of these
e
An object at rest may also have A) speed. B) velocity. C) momentum. D) kinetic energy. E) potential energy
e
Compared to a 1-kg block of solid iron, a 2-kg block of solid iron has the same a) mass b) volume c) weight d) all of these e) none of these
e
The Earth pulls on the moon. Similarly the moon pulls on the Earth, evidence that a) these two pulls comprise an action-reaction pair b) the earth is larger so its pull is larger c) the moon is smaller so its d) larger objects pull harder
a
The ball rolling down an incline has its maximum potential energy at A) the top. B) a quarter of the way down. C) halfway down. D) the bottom
a
The direction of a gravitational field is a) in the same direction as the gravitational attraction b) away from the center of gravity of an object c) opposite to the direction of gravitational attraction
a
The force required to maintain an object at a constant velocity in free space is equal to a) zero b) the mass of the object c) the weight of the object d) the force required to stop it e) none of these
a
The newton is a unit of a) force b) mass c) density d) inertia
a
Two billiard balls having the same mass roll toward each other, each moving at the same speed. What is the combined momentum of the two balls? A) 0 kg m/s. B) 10 kg m/s. C) more information need to determine.
a
Which requires the most amount of work by the brakes of a car? A) slowing down from 100 km/h to 70 km/h B) slowing down from 70 km/h to a stop C) equal amounts for either
a
When a rock thrown straight upwards gets to the exact top of its path, its a) velocity is zero and its acceleration is zero b) velocity is zero and its acceleration is about 10 meters per second per second c) velocity is about 10 m/s and its acceleration is zero d) velocity is about 10 m/s and its acceleration is about 10 meters per second per second e) none of these
b
The Earth's gravitational field extends a) only above and beyond the Earth's surface and cancels inside the Earth b) both inside and outside the Earth and throughout the entire universe c) neither of these
b
The amount of gravitational force that acts on the space shuttle while in orbit is a) nearly zero b) almost as much as the shuttle's weight on the Earth's surface c) the same as the shuttle's weight on the Earth's surface
b
The concept of force is not fundamental to a) Newton's theory of gravitation b) Einstein's theory of gravitation c) both of these d) neither of these
b
The difference between impulse and impact force involves the A) distance the force acts. B) time the force acts. C) difference between acceleration and velocity. D) mass and its effect on resisting a change in momentum.
b
The force exerted by the road on each tire of an accelerating car a) equals the combined force of all four tires on the road b) is less than the combined force of all four tires on the road c) is more than the combined force on all four tires on the road
b
The force of gravity acting on you will increase if you a) burrow deep inside the planet b) stand on a planet with a radius that is shrinking c) both of these d) none of these
b
The impulse-momentum relationship is a direct result of A) Newton's 1st law. B) Newton's 2nd law. C) Newton's 3rd law.
b
Which of the following has the largest momentum relative to the Earth? A) a tightrope walker crossing Niagara Falls B) a pickup truck speeding along a highway C) a Mack truck parked in a parking lot D) the Science building on campus E) a dog running down the street
b
Which of the following is not a vector quantity? a) velocity b) speed c) acceleration d) All are vector quantities
b
a prize fighter ungloved fist can do more damage to a jaw than a gloved fist. The reason for this is that the ungloved fist a) delivers a larger impulse to the jaw b) exerts a shorter impulse to the jaw c) has less air resistance d) none of these
b
lnside a freely-falling elevator, there would be no A) gravitational force on you. B) apparent weight for you C) both of these D) none of these
b
A automobile and a baby carriage traveling at the same speed collide head-on. the impact force is a) greater on the automobile b) greater on the baby carriage c) the same for both
c
A black hole is a) an empty region of space with a huge gravitational field a) a small region that contains the mass of many galaxies c) simply the remains of a giant star that has undergone gravitational collapse
c
Newton discovered A) gravity. B) that gravity is universal. C) neither
b
A Mack truck and a Volkswagen traveling at the same speed have a head-on collision. the vehicle that undergoes the greatest change in velocity will be the a) Volkswagen b) Mack truck c) same for both
a
A coconut and a feather fall from a tree through the air to the ground below. The amount of air-resistance force is a) greater on the coconut b0 greater on the feather c) the same on each
a
A force is a vector quantity because it has both a) magnitude and direction b) mass and acceleration c) action and reaction counterparts
a
A golf ball is thrown at and bounces backward from a massive bowling ball that is initially at rest. After the collision, compared to the golf ball, the bowling ball has a) more momentum, but less kinetic energy b) more kinetic energy, but less momentum c) more momentum and more kinetic energy d) less momentum and less kinetic energy e) not enough information is given to say
a
A hydraulic press, like a wheel and axle, is capable of multiplying force input a) always true b) always false c) sometimes true d) sometimes false
a
A skydiver's terminal velocity will be greatest if she falls a) head first b) lying flat on her back c) lying flat on her stomach d) with her parachute open
a
An asteroid exerts at 360-N gravitational force on a nearby spacecraft. This force is directed a) toward the asteroid b) away from the asteroid c) toward the sun
a
An object is placed exactly halfway between the Earth and moon. The object will fall toward the a) Earth b) moon c) neither of these
a
An object that has kinetic energy must be A) moving. B) falling. C) at an elevated position. D) at rest. E) none of these
a
Galileo's use of inclined planes allowed him to effectively a) slow down the acceleration of free fall b) increase the acceleration beyond that of free fall c) eliminate the acceleration of free fall d) eliminate friction
a
If a monkey floating in outer space throws his hat away, the hat and the monkey will both A) move away from each other, but at different speeds B) move away from each other at the same speed C) move a short distance and then slow down D) move a short distance and then go faster E) come to a stop after a few minutes
a
If more horizontal force is applied to a sliding object than is needed to maintain a constant velocity a) the object accelerates in the direction of the applied force b) the object accelerates opposite the direction of the applied force c) the friction force increases d) two of the above e) none of the above
a
If the mass of the Earth somehow increased with no change in radius, your weight would A) increase also. B) decrease. C) stay the same.
a
If the speed of a moving object doubles, which of the following also doubles? A) momentum B) kinetic energy C) acceleration D) all of the above
a
If you push an object a given distance, while applying twice the force, you do A) twice as much work. B) four times as much work. C) the same amount of work. D) half as much work.
a
If you push an object twice as far while applying the same force, you do A) twice as much work. B) four times as much work. C) the same amount of work. D) half as much work.
a
If you push for a half hour or a whole hour against a stationary wall, A) no work is done in either case. B) half as much work is done during the half hour. C) twice as much work is done during the half hour. D) it is impossible to determine how much work is done.
a
Padded dashboards in cars are safer in an accident than nonpadded ones because an occupant hitting the dash has A) increased time of impact. B) decreased impulse. C) decreased impact force. D) a and b above. E) a and c above.
a
Suppose a gun were made of a strong but very light material. Suppose also that the bullet is more massive than the gun itself. For such a weapon A) the target would be safer than the shooter. B) recoil problems would be lessened. C) conservation of energy would not hold. D) conservation of momentum would not hold. E) both conservation of energy and momentum would not hold.
a
A block of ice sliding down an incline has its maximum speed at A) the top. B) the bottom. C) halfway down. D) difficult to predict without knowing the slope of the incline E) difficult to predict without knowing the coefficient of friction
b
A flower pot of mass m falls from rest to the ground below, a distance h. Which statement is correct? A) The speed of the pot when it hits the ground is proportional to h. B) The KE of the pot when it hits the ground is proportional to h. C) The KE of the pot when it hits the ground does not depend on m. D) The speed of the pot when it hits the ground depends on m. E) None of these are correct.
b
A heavy object and a light object are dropped at the same time from rest in a vacuum. The heavier object reaches the ground: a) sooner than the lighter object b) at the same time as the lighter object c) later than the lighter object d) almost immediately
b
A skydiver jumps from a high-flying plane. As her velocity of fall increases, her acceleration a) increases b) decreases c) remains unchanged regardless of air resistance
b
According to Newton, the greater the masses of interacting objects, the A) less the gravitational force between them. B) greater the gravitational farce between them. C) greater the force between them by the square of the masses.
b
An astronaut, floating alone in outer space, throws a baseball. If the ball floats away at a speed of 20 meters per second, the astronaut will A) move in the opposite direction at a speed of 20 m/s B) move in the opposite direction, but at a lower speed C) move in the opposite direction but at a higher speed D) not move as stated in any of the above choices
b
An object following a straight-line path at constant speed a) has a net force acting upon it in the direction of motion b) has zero acceleration c) has no forces acting on it d) none of these
b
Compared to falling on a wooden floor, a wine glass may not break when it falls to a carpeted floor because of the A) lesser impulse in stopping. B) longer time to stop. C) both of these. D) neither of these.
b
If a ball is thrown upwards and returns to the same position. Compared with its original speed after release, its speed when it returns is about a) half as much b) the same c) twice as much d) four times as much
b
If an object is raised twice as high, its potential energy will be A) half as much B) twice as much. C) four times as much. D) impossible to determine unless the time is given.
b
If an object moves with constant acceleration, its velocity must a) be constant also b) change by the same amount each second c) change by varying amounts depending on its speed d) always decrease
b
If an object's mass is decreasing while a constant force is applied to the object, the acceleration a) decreases b) increases c) remains the same
b
If the Earth's mass decreased to one-half its original mass with no change in radius, then your weight would a) decrease to one quarter your original weight b) decrease to one half your original weight c) stay the same d) none of these
b
If you drop an object, it will accelerate downward at a rate of 9.8 meters per second per second. If you instead throw it downwards, it acceleration (in the absence of air resistance) will be a) less than 9.8 meters per second per second b) 9.8 meters per second per second c) greater than 9.8 meters per second per second
b
It is correct to say that impulse is equal to A) momentum. B) the change in momentum. C) the force multiplied by the distance the force acts. D) all of these. E) none of these.
b
