Question 1

The scientist to first introduce the concept of inertia was

Accepted Answer

Galileo was the first to introduce the concept of inertia in his work on motion and was the first to understand that an object will remain at rest or in uniform motion in a straight line unless acted upon by an external force. Although Aristotle had some understanding of motion, he did not introduce the concept of inertia. Newton built on Galileo's work and developed the laws of motion. Copernicus is known for his work on heliocentrism, which revolutionized astronomy, but not for introducing the concept of inertia.

Question 2

Hang from a pair of gym rings and the upward support forces of the rings will always

Accepted Answer

The upward support forces from the rings must add up to equal your weight to balance the downward force of gravity acting on you.

Question 3

A man weighing 800 N stands at rest on two bathroom scales so that his weight is distributed evenly over both scales.The reading on each scale is

Accepted Answer

When the man stands on two scales, his weight is distributed evenly between them. Therefore each scale will show half of his weight. So the reading on each scale will be 400 N.

Question 4

If no external forces are acting on a moving object,it will

Accepted Answer

According to Newton's first law of motion, an object in motion will continue moving at the same velocity unless acted upon by an external force.

Question 5

When you stand at rest on a pair of bathroom scales,the readings on the scales will always

Accepted Answer

When standing on two scales, your weight is distributed between them, so the sum of the readings on both scales will equal your total weight.

Question 6

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

Accepted Answer

Inertia is the tendency of an object to resist any change in its state of rest or motion. In this case, even though the engine has stopped due to lack of fuel, the car still has a certain amount of motion due to inertia, which allows it to keep moving for some distance.

Question 7

According to Newton's law of inertia,a railroad train in motion should continue going forever even if its engine is turned off.We never observe this because railroad trains

Accepted Answer

Newton's law of inertia states that an object in motion will stay in motion with a constant velocity unless acted upon by an external force. In the case of a railroad train, there are always opposing forces that act upon it such as friction, air resistance, and gravity. These forces eventually bring the train to a stop, rather than allowing it to continue moving forever.

Question 8

Whirl a rock at the end of a string and it follows a circular path.If the string breaks,the tendency of the rock is to

Accepted Answer

If the string breaks, the rock would no longer be attached to a centripetal force that keeps it moving in a circular path. Therefore, the rock would continue to move in a straight line path due to its inertia.

Question 9

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

Accepted Answer

The horizontal speed of the package remains constant at 30 m/s because there is no horizontal force acting on it (neglecting air resistance).

Question 10

The force of friction on a sliding object is 10 N.The applied force needed to maintain a constant velocity is

Accepted Answer

According to Newton's first law of motion, an object at rest or in uniform motion will remain so unless acted upon by an external force. In this scenario, the object is already in motion and is experiencing a frictional force of 10 N in the opposite direction of its motion. To maintain a constant velocity, an applied force equal to the force of friction (10 N) in the direction of motion is needed. Therefore, the applied force needed is also 10 N, which is option C.

Question 11

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

Accepted Answer

This phenomenon is due to the milk carton's inertia, which is the tendency of an object to resist a change in its state of motion. When the paper is quickly jerked out from under the carton, the paper's frictional force is not enough to overcome the inertia of the milk carton and cause it to tip over. This demonstrates the principle of inertia. None of the other choices explain this phenomenon.

Question 12

A 300-kg bear grasping a vertical tree slides down at constant velocity.The friction force between the tree and the bear is

Accepted Answer

The answer of A 300-kg bear grasping a vertical tree...

Question 13

Whereas Aristotle relied on logic in explaining nature,Galileo relied on

Accepted Answer

Galileo relied on experimentation to understand nature, using the scientific method to observe and test theories. This was a departure from Aristotle's reliance on logic and reasoning, without empirical evidence. Galileo also used mathematics to describe the patterns he observed in nature, but experimentation was his primary tool for understanding the physical world.

Question 14

When a rocket ship accelerating in outer space runs out of fuel,it

Accepted Answer

Once the rocket ship runs out of fuel, there is no longer any force propelling it forward. Therefore, it can no longer accelerate and will continue to move at a constant velocity until acted upon by an external force.

Question 15

An object in mechanical equilibrium is an object

Accepted Answer

An object in mechanical equilibrium is an object that is both at rest and has no acceleration, which also means that it is moving with constant velocity. Therefore, all of the choices (A, B, and C) are correct.

Question 16

Galileo's use of inclined planes allowed him to effectively

Accepted Answer

Galileo's use of inclined planes allowed him to slow down the acceleration of free fall. By changing the angle of the inclined plane, he could reduce the steepness of the slope and therefore reduce the speed at which objects moved down it. This allowed for more accurate measurements of motion and the development of new theories about gravity and acceleration.

Question 17

A truck is moving at constant velocity.Inside the storage compartment,a rock is dropped from the midpoint of the ceiling and strikes the floor below.The rock hits the floor

Accepted Answer

Since the truck is moving at a constant velocity, we can assume there is no acceleration. Therefore, there is no force acting on the rock except for gravity. As a result, the rock will fall straight down from the midpoint of the ceiling and hit the floor directly below it. The horizontal velocity of the truck does not affect the vertical motion of the rock. Therefore, it hits the floor directly below the midpoint of the ceiling.

Question 18

Galileo's interpretation of motion differed from Aristotle's in that Galileo emphasized

Accepted Answer

The answer of Galileo's interpretation of motion differed from Aristotle's...

Quiz 2: Newtons First Law of Motion: Inertia