Exam 1: Chapters 3 - 9
A horse gallops a distance of 10 kilometers in a time of 30 minutes. Its average speed is 15 km/h. 40 km/h. 20 km/h. 30 km/h.
20 km/h.
An object that has kinetic energy must be at an elevated position. at rest. falling. moving. none of these
moving.
A torque acting on an object tends to produce linear motion. velocity. a center of gravity. equilibrium. rotation.
rotation.
A car maintains a constant velocity of 100 km/hr for 10 seconds. During this interval its acceleration is 10 km/hr. 110 km/hr. 1000 km/hr. zero.
zero
A sack of potatoes weighing 200 N falls from an airplane. As the velocity of fall increases, air resistance also increases. When air resistance equals 200 N, the sack's acceleration in meters per second per second is 9.8. 4.9. none of these 0. infinite.
0
An object covers a distance of 8 meters in the first second of travel, another 8 meters during the next second, and 8 meters again during the third second. Its acceleration in meters per second per second is approximately 5. 0. 8. 24.
0
A car moving at 50 km/hr skids 20 m with locked brakes. How far will the car skid with locked brakes if it were traveling at 150 km/hr? 180 m 90 m 20 m 60 m 120 m
180 m
The impulse-momentum relationship is a direct result of Newton's 1st law. Newton's 4th law. Newton's 3rd law. Newton's 2nd law.
Newton's 2nd law.
When an object is in motion, which of the following could not have a value of zero? momentum inertia None of the above could be zero. mass kinetic energy
None of the above could be zero.
In science, a theory is less than a fact. a synthesis of a large body of well-tested knowledge. an educated guess. unchangeable
a synthesis of a large body of well-tested knowledge.
A package falls off a truck that is moving at 30 m/s. Neglecting air resistance, the horizontal speed of the package just before it hits the ground is about 30 m/s. More information is needed for an estimate. more than 30 m/s. zero. less than 30 m/s but larger than zero.
about 30 m/s.
No force due to Earth's gravity is acting on the astronauts inside the orbiting space shuttle. This statement is sometimes true while in orbit. always false. always true while in orbit.
always false.
Inside a freely falling elevator, there would be no gravitational force on you. both of these none of these apparent weight for you.
apparent weight for you.
The two measurements necessary for calculating average speed are acceleration and time. velocity and time. distance and time. velocity and distance. distance and acceleration.
distance and time.
If a turntable's rotational speed is doubled, then the linear speed of a pet hamster sitting on the edge of the record will halve. remain the same. double.
double
A player catches a ball. Consider the action force to be the impact of the ball against the player's glove. The reaction to this force is the player's grip on the glove. none of these force the glove exerts on the ball. friction of the ground against the player's shoes. muscular effort in the player's arms.
force the glove exerts on the ball.
If the mass of the Earth somehow increased with no change in radius, your weight would increase also. stay the same. decrease.
increase also.
If your automobile runs out of fuel while you are driving, the engine stops but you do not come to an abrupt stop. The concept that most explains why is gravity. acceleration. resistance. inertia.
inertia
If one object has twice as much mass as another object, it also has twice as much acceleration due to gravity. all of these velocity. volume. inertia.
inertia.
For an action force, there must be a reaction force that always acts in the same direction. is exactly equal in magnitude. is slightly smaller in magnitude than the action force. is slightly larger in amplitude than the action force.
is exactly equal in magnitude.
The main reason ocean tides exist is that the pull of the moon is greater on the Earth because the moon is closer to Earth. is greater on oceans closer to the moon and less on oceans farther from the moon. and sun are in conjunction at high tides and in opposition at low tides. and the sun on the oceans are in opposite directions. none of these
is greater on oceans closer to the moon and less on oceans farther from the moon.
A large metal ball is shot from a cannon with a short barrel. If the same ball were to be shot from cannon with a longer barrel, its muzzle velocity would be impossible to determine without additional information. the same. more. less.
more.
Horses that move with the fastest linear speed on a merry-go-round are located anywhere, because they all move at the same speed. near the center. near the outside.
near the outside.
Suppose you are at the center of a large freely-rotating horizontal turntable in a carnival funhouse. As you crawl toward the edge, the angular momentum of you and the turntable none of these remains the same, but the RPMs decrease. decreases in direct proportion to your decrease in RPMs. decreases. increases.
remains the same, but the RPMs decrease.
A rifle recoils while firing a bullet. The speed of the rifle's recoil is small because the rifle has much more mass than the bullet. momentum is mainly concentrated in the bullet. force against the rifle is smaller than against the bullet. momentum of the rifle is smaller.
rifle has much more mass than the bullet.
A sheet of paper can be withdrawn from under a container of milk without toppling it if the paper is jerked quickly. This best demonstrates that the milk carton has inertia. gravity tends to hold the milk carton secure. the milk carton has no acceleration. there is an action-reaction pair of forces. none of these
the milk carton has inertia.
A automobile and a baby carriage traveling at the same speed collide head-on. The impact force is the same for both. greater on the automobile. greater on the baby carriage.
the same for both.
The synthesis of a large collection of information that contains well-tested and verified hypotheses about certain aspects of the world is known as a scientific hypothesis. fact. none of these theory. law or principle.
theory
Earth pulls on the moon. Similarly the moon pulls on Earth, evidence that larger objects pull harder. Earth is larger so its pull is larger. these two pulls comprise an action-reaction pair. the moon is smaller so its pull is smaller.
these two pulls comprise an action-reaction pair.
If you do work on an object in one-third the usual time, your power output is three times the usual power output. one third the usual power output. impossible to predict without additional information. the usual power output.
three times the usual power output.
The power required to exert 1 N force, over a distance of 1 m in 1 second is none of these 2 W. 3 W. 1/3 W. 1 W.
1 W.
A bungee jumper attains a speed of 30 m/s just as the bungee cord begins to stretch. If the period of stretch is 2 s, the magnitude of the jumper's average deceleration is about 1.5 g. g. none of these 2 g. 0.5 <i>g</i>.
1.5 g.
The force of friction on a sliding object is 10 newtons. The applied force needed to maintain a constant velocity is less than 10 N. more than 10 N. 10 N.
10 N.
A 10-kg brick and a 1-kg book are dropped in a vacuum. The force of gravity on the 10-kg brick is the same as the force on the 1-kg book. zero. 10 times as much. one-tenth as much.
10 times as much.
An asteroid exerts a 360-N gravitational force on a nearby spacecraft. If the spacecraft moves to a position three times as far from the center of the asteroid, the force will be 40 N. 1080 N. 360 N. 120 N. zero.
40 N.
An object is pulled northward by a force of 10 N and at the same time another force of 15 N pulls it southward. The magnitude of the resultant force on the object is 5 N. 25 N. 0 N. 150 N.
5 N.
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 Suzie, surprisingly. Arnold, of course. both the same, interestingly enough.
both the same, interestingly enough.
A freight train rolls along a track with considerable momentum. If it rolls at the same speed but has twice as much mass, its momentum is quadrupled. doubled. unchanged. zero.
doubled
An industrial flywheel has a greater rotational inertia when most of its mass is nearest the rim. nearest the axis. uniformly spread out as in a disk.
nearest the rim.
When a rock thrown straight upwards gets to the exact top of its path, its velocity is zero and its acceleration is zero. velocity is about 10 m/s and its acceleration is about 10 meters per second per second. velocity is zero and its acceleration is about 10 meters per second per second. none of these velocity is about 10 m/s and its acceleration is zero.
velocity is zero and its acceleration is about 10 meters per second per second.