Quiz: Newton's Laws
Fixed with All CORRECT Answer
Question 1
2 / 2 pts
For this situation, I push on a heavy chair. Suppose I push lightly on the chair, and the chair
doesn’t move at all. Then the strength of the force the chair exerts on me is : equal to the force
I exert on the chair.
Question 2
2 / 2 pts
Two identical airplanes are executing identical turns around a pylon. One of them is moving at
200 mph, and the other is moving at 100 mph. The centripetal force acting on the airplane
moving at 200 mph is __________ the value of the centripetal force acting on the airplane
moving at 100 mph.: Four times
Rationale:Centripetal force = mv2 / r; since v1 = 2v2 ; the force is (2)2 or 4 times as great.
Question 3
2 / 2 pts
The symbol G is used to represent : the universal gravitational constant.
Incorrect
Question 4
0 / 2 pts
As a body falls through air starting from rest, its acceleration: gets smaller and smaller,
eventually approaching zero.
Question 5
2 / 2 pts
For this situation, I push on a heavy chair.
Suppose I push moderately on the chair, and this time the chair does move. Then the strength of
the force the chair exerts on me is : equal to the force I exert on the chair.
Question 6
2 / 2 pts
Starting from rest, a 20,000-kg aircraft being launched from an aircraft carrier goes from 0 to 90
m/s in 2 seconds. The net force acting on the aircraft is Answer: 900,000 N.
Rationale: F = ma; a = change in velocity/change in time = 90 m/s / 2 seconds = 45 m/s2 F =
20,000 kg x 45 m/s2 = 900,000 N
Question 7
2 / 2 pts
Two identical cars are traveling around the same curve on a highway. One of them is moving at
60 mph, and the other is moving at 30 mph. The centripetal force acting on the car moving at 60
mph is __________ the value of the centripetal force acting on the car moving at 30 mph.
Answer: four times
Question 8
2 / 2 pts
The horizontal acceleration of a projectile Answer: is zero.
Question 9
2 / 2 pts
A body on the surface of the Earth weighs 400 lb. The radius of the Earth is about 4,000 miles. If
this same body were placed on a 4,000-mile-high tower, its weight would be Answer: 100 lbs.
Question 10
2 / 2 pts
If object A has more mass than object B, Answer: all of the above
Question 11
2 / 2 pts
If the net force on an object is zero, Answer: the object’s acceleration must be zero.
Question 12
2 / 2 pts
During the period of one day, the number of high tides at a given point is about Answer: Two.
Question 13
2 / 2 pts
As a space shuttle is launched into orbit, the direction of its accelerationAnswer: varies between
pointing upward and pointing downward.
Question 14
2 / 2 pts
The force needed to make an object move in a circle is: Centripetal Force. Answer
Question 15
2 / 2 pts
Which statement is incorrect? Rationale: A - D are all true.
Question 16
2 / 2 pts
A satellite orbiting the Earth in a circular orbit at 400 miles from the center of Earth is moved to
a distance of 1,200 miles from the center of Earth. The gravitational force between the Earth and
satellite changes by a factor of 3. False
Rationale: False, it changes by a factor of 32 = 9.
Question 17
2 / 2 pts
When an object reaches its terminal speed, its acceleration is zero. Answer: True
Question 18
2 / 2 pts
When a car goes around a curve at twice the speed, the centripetal force on the car doubles.
Answer: False
Incorrect
Question 19
0 / 2 pts
A newton is larger than a pound. Answer: False
Question 20
2 / 2 pts A body is oscillating up and down at the end of a spring. Let’s consider when the
body is at the top of its up-and-down motion. The acceleration is zero. Answer: False
Question 21
2 / 2 pts
All forces have specific directions associated with them. Answer: True
Incorrect
Question 22
0 / 2 pts
An aircraft weighing 1,500 N is accelerated at 15 m/s 2, the force acting on the aircraft is
approximately 2,296 N. Answer: True
Rationale:The mass of the aircraft is 1,500 N/9.8 m/s 2 = 153.061 kg; F = ma = 153.061 kg
15 m/s 2 = 2295.9 N
Question 23
2 / 2 pts
You throw a ball straight up, it peaks out and then comes back down to you. During this motion,
the velocity and acceleration always point in the same direction. Answer: False
Incorrect
Question 24
0 / 2 pts
To hold a 5 lb bag of sugar in your hand, you must push upwards on it with a force of 5 lb. This
is an example of Newton’s third law. True : Correct Answer
Question 25
2 / 2 pts
A ball on a string is being whirled around overhead when the string breaks. The ball will move
in the direction of the centripetal force the moment the string breaks.
False
Rationale: False, the ball will move in the direction of the velocity vector when the string
breaks.
Partial
Question 26
9 / 15 pts
Select the closest matching pairs possible. 3 pts for each response.
Newton's First Law
An object remains in motion or at rest unless acted upon by an exterior Force
Newton's 2nd Law
F=ma
Newton's 3rd Law
If Object A causes a force on object B then Object exerts an equal force in the
opposite direction on A.
Newton's Law of Universal Gravitation
Every Object exerts Gravitational Pull
