42 Questions

Final exam

Questions and Answers

- 1.Science is a body of knowledge that
- A.
Condenses knowledge into testable laws

- B.
Describes order in nature

- C.
Is an ongoing activity of humans

- D.
All of the above choices are correct

- E.
None of the above choices are correct

- 2.As an object freely falls downward, its
- A.
Acceleration increases

- B.
Velocity increases

- C.
Both of these

- D.
None of these

- 3.A sheet of paper can be withdrawn from under a container of milk without toppling it if the paper is jerked quickly.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
- A.
The milk carton has inertia

- B.
The milk carton has no acceleration

- C.
There is an action-reaction pair of forces

- D.
Gravity tends to hold the milk carton secure

- E.
None of these

- 4.The gain in speed each second for a freely-falling object is about
- A.
0

- B.
20 m/s

- C.
5 m/s

- D.
10 m/s

- E.
Depends on the initial speed

- 5.A package falls of 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
- A.
More than 30 m/s

- B.
Zero

- C.
Less than 30 m/s but larger than zero

- D.
About 30 m/s

- E.
More information is needed for an estimate

- 6.According to Newton's law of inertia, a rail road train in motion should continue going forever even if its engine is turned off. We never observe this because railroad trains.
- A.
Are much too heavy

- B.
Move too slowly

- C.
Must go up and down hills

- D.
Always have forces that oppose their motion

- 7.A scientific statement that can never be changed is a scientific
- A.
Principle

- B.
Theory

- C.
Hypothesis

- D.
Law

- E.
None of the above choices are correct

- 8.If no external forces are acting on a moving object it will
- A.
Continue moving at the same velocity

- B.
Move slower and slower until it finally stops

- C.
Continue moving at the same speed

- 9.Galileo's use of inclined planes allowed him to effectively
- A.
Eliminate the acceleration of free fall

- B.
Increase the acceleration beyond that of free fall

- C.
Slow down the acceleration of free fall

- D.
Eliminate friction

- 10.The two measurements necessary for calculating average speed are
- A.
Distance and acceleration

- B.
Velocity and distance

- C.
Acceleration and time

- D.
Velocity and time

- E.
Distance and time

- 11.A horse gallops a distance of 10 kilometers in a time of 30 minutes. It's average speed is
- A.
15 km/h

- B.
30 km/h

- C.
20 km/h

- D.
40 km/h

- 12.A car maintains a constant velocity of 100 km/hr for 10 seconds. During this interval it acceleration is
- A.
Zero

- B.
1000 km/hr

- C.
110 km/hr

- D.
10 km/hr

- 13.A hockey puck is set in motion across a frozen pond. If ice friction and air resistance are neglected the force required to keep the puck sliding at constant velocity is
- A.
Equal to its weight divided by its mass

- B.
Zero

- C.
Equal to the product of its mass times its weight

- D.
Equal to its weight

- 14.Twelve seconds after starting from rest, an object falling freely will have a speed of
- A.
50 m/s

- B.
100 m/s

- C.
10 m/s

- D.
More than 100 m/s

- 15.If an object moves with constant acceleration, its velocity must
- A.
Be constant also

- B.
Change by the same amount each second

- C.
Always decrease

- D.
Change b varying amounts depending on its speed

- 16.A ball tossed vertically upward rises, reaches its highest point, and then falls back to its starting point. During this time the acceleration of the ball is always
- A.
Opposite its velocity

- B.
Directed downward

- C.
In the direction of motion

- D.
Directed upward

- 17.If a car accelerates form rest at 2 meters per second per second, its speed 3 seconds later will be about
- A.
2 m/s

- B.
6 m/s

- C.
4 m/s

- D.
3 m/s

- 18.At on instant an object in free fall is moving downward at 50 meters per second. One second later is speed should be about
- A.
25 m/s

- B.
100 m/s

- C.
55 m/s

- D.
60 m/s

- E.
50 m/s

- 19.Starting from rest, the distance a freely-falling object will fall in 1.0 second is about
- A.
10 m

- B.
2.00 m

- C.
5.0 m

- D.
None of the above

- 20.An object falls freely from rest on a planet where the acceleration due to gravity is 20 meters per second squared. After 5 seconds, the object will have a speed of
- A.
20 m/s

- B.
10 m/s

- C.
50 m/s

- D.
5 m/s

- E.
100 m/s

- 21.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, its acceleration (in the absence of air resistance and after it leaves your hand) will be
- A.
Greater than 9.8 meters per second per second

- B.
Less than 9.8 meters per second per second

- C.
9.8 meters per second per second

- 22.If a projectile is fired straight up at a speed of 10 m/s, the total time to return to its starting position is about
- A.
2 seconds

- B.
20 seconds

- C.
10 seconds

- D.
1 second

- E.
Not enough information to estimate

- 23.When a rock thrown straight upwards gets tot he exact top of its path, its
- A.
Velocity is zero and its acceleration is zero

- B.
Velocity is about 10 m/s and its acceleration is zero

- C.
Velocity is zero and its acceleration is about 10 meters per second per second

- D.
Velocity is about 10 m/s and its acceleration is about 10 meters per second per second

- E.
None of these

- 24.A ball is thrown upwards. Neglecting air resistance, what initial upward speed does the ball need to remain in the air for a total time of 10 seconds?
- A.
About 80 m/s

- B.
About 60 m/s

- C.
About 110 m/s

- D.
About 100 m/s

- E.
About 50 m/s

- 25.Which has a greater mass?
- A.
An automobile battery

- B.
A king-size pillow

- C.
Neither- both have the same

- 26.Strange as it may seem, it is just as hard to accelerate a car on a level surface on the oon as it is here on the Earth. This is because
- A.
The weight of the car is independent of gravity

- B.
The mass of the car is independent of gravity

- C.
Nonsense! a car is much more easily accelerated on the moon than on the Earth

- 27.The newton is a unit of
- A.
Force

- B.
Inertia

- C.
Density

- D.
Mass

- 28.A rock weighs 30 N on Earth. A second rock weighs 30 N on the moon. Which of the two rocks has the greater mass? (gravity on the moon is one-sixth of that on Earth)
- A.
The one on the moon

- B.
The one on Earth

- C.
They have the same mass

- D.
Not enough information to say

- 29.A 10-kg brick and 1-kg book are dropped in a vacuum. The force of gravity on the 10-kg brick is
- A.
Zero

- B.
The same as the force on the 1-kg book

- C.
One-tenth as much

- D.
10 times as much

- 30.The force of friction on a sliding object is 10 newtons. The applied force needed to maintain a constant velocity is
- A.
Less than 10 N

- B.
More than 10 N

- C.
10 N

- 31.Whenever the net force on an object is zero, its acceleration
- A.
Is zero

- B.
May be less than zero

- C.
May be more than zero

- 32.A 1-kg mass at the earth's surface weighs
- A.
1 N

- B.
4.9 N

- C.
10.8 N

- D.
9.8 N

- E.
None of these

- 33.A 10-N falling object encounters 4 N of air resistance. The net force on the object is
- A.
4 N

- B.
10 N

- C.
6 N

- D.
0 N

- E.
None of these

- 34.An object is propelled along a straight-line path by a force. If the net force were doubled, the object's acceleration would be
- A.
Four times as much

- B.
Half as much

- C.
Twice as much

- D.
The same

- E.
None of these

- 35.An object is propelled along a straight-line path in space by a force. If the mass of the object somehow becomes twice as much, its acceleration
- A.
Halves

- B.
Doubles

- C.
Quadruples

- D.
Stays the same

- E.
None of these

- 36.Hang from a pair of gym rings and the upward support forces of the rings will always
- A.
Each be equal to your weight

- B.
Add up to equal your weight

- C.
Each be half your weight

- 37.A tow truck exerts a force of 3000 N on a car, accelerating it at 2 meters per second per second. What is the mass of the car?
- A.
1500 kg

- B.
500 kg

- C.
1000 kg

- D.
3000 kg

- E.
None of these

- 38.An object following a straight-line path at constant speed
- A.
Has zero acceleration

- B.
Has a net force acting upon it in the direction of motion

- C.
Has no forces acting on it

- D.
None of these

- 39.Suppose a particle is being accelerated through space by a 10-N force. Suddenly the particle encounters a second force of 10 N in the opposite direction from the first force. The particle with both forces acting on it
- A.
Theoretically tends to accelerate toward the speed of light

- B.
Decelerates gradually to a halt

- C.
Is brought to a rapid halt

- D.
Continues at the speed it had when it encountered the second force

- E.
None of these

- 40.The brakes of a speeding truck are slammed on and it skids to a stop. If the truck were heavily loaded so that it had twice the total mass, the skidding distance would be
- A.
4 times as far

- B.
2 times as far

- C.
1/2 as far

- D.
1 1/2 times as far

- E.
The same

- 41.If you are driving at 20 m/s and slam on your brakes and skid at 0.5 g (5m/s/s) to a full stop, the skidding time in seconds is
- A.
About 5

- B.
About 6

- C.
About 4

- D.
About 3

- E.
More than 6

- 42.If more horizontal force is applied to a sliding object than is needed to maintain a constant velocity,
- A.
The friction force increases

- B.
The object accelerates opposite the direction of the applied force

- C.
The object accelerates in the direction of the applied force

- D.
Two of the above

- E.
None of the above