Video 1 Newtons First Law Of Motion

1. __________ is the tendency of an object to resist changes in its state of motion.

Inertia is the tendency of an object to resist changes in its state of motion. This means that an object at rest will stay at rest, and an object in motion will continue moving at a constant velocity, unless acted upon by an external force. Inertia is a fundamental property of matter and is related to an object's mass. The greater the mass of an object, the greater its inertia, and the more force is required to change its motion. Inertia is an important concept in physics and helps explain why objects behave the way they do when forces are applied to them.

Explanation

Inertia is the tendency of an object to resist changes in its state of motion. This means that an object at rest will stay at rest, and an object in motion will continue moving at a constant velocity, unless acted upon by an external force. Inertia is a fundamental property of matter and is related to an object's mass. The greater the mass of an object, the greater its inertia, and the more force is required to change its motion. Inertia is an important concept in physics and helps explain why objects behave the way they do when forces are applied to them.

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2. To determine if the forces acting upon an object are balanced or unbalanced, an analysis must first be conducted to determine what forces are acting upon the object and in what direction.

True

False

The explanation for the given correct answer is that in order to determine if the forces acting upon an object are balanced or unbalanced, it is necessary to conduct an analysis to identify the forces acting upon the object and their respective directions. This analysis helps to determine whether the forces cancel each other out and result in a balanced situation, or if there is a net force causing an unbalanced situation. Therefore, the statement that an analysis is required to determine the balance or imbalance of forces is true.

Explanation

The explanation for the given correct answer is that in order to determine if the forces acting upon an object are balanced or unbalanced, it is necessary to conduct an analysis to identify the forces acting upon the object and their respective directions. This analysis helps to determine whether the forces cancel each other out and result in a balanced situation, or if there is a net force causing an unbalanced situation. Therefore, the statement that an analysis is required to determine the balance or imbalance of forces is true.

3. Imagine a place in the space far from all gravitational and frictional influences. Suppose that you visit that place (just suppose) and throw a rock. The rock will

Gradually stop.

Continue in motion in the same direction at constant speed.

Will not move.

None of the above.

According to Newton's first law, the rock will continue in motion in the same direction at constant speed.

Explanation

According to Newton's first law, the rock will continue in motion in the same direction at constant speed.

4. Mac and Tosh are arguing in the cafeteria. Mac says that if he flings the Jell-O with a greater speed it will have a greater inertia. Tosh argues that inertia does not depend upon speed, but rather upon mass. Who do you agree with?

Mac

Tosh

None of the above.

Tosh is correct. Inertia is that quantity which depends solely upon mass. The more mass, the more inertia. Momentum is another quantity in Physics which depends on both mass and speed. Momentum will be discussed in a later unit.

Explanation

Tosh is correct. Inertia is that quantity which depends solely upon mass. The more mass, the more inertia. Momentum is another quantity in Physics which depends on both mass and speed. Momentum will be discussed in a later unit.

5. Supposing you were in space in a weightless environment, would it require a force to set an object in motion?

Yes.

No.

None of the above.

Absolutely yes!

Even in space objects have mass. And if they have mass, they have inertia. That is, an object in space resists changes in its state of motion. A force must be applied to set a stationary object in motion. Newton's laws rule - everywhere!

Explanation

Absolutely yes!

Even in space objects have mass. And if they have mass, they have inertia. That is, an object in space resists changes in its state of motion. A force must be applied to set a stationary object in motion. Newton's laws rule - everywhere!

6.

A group of physics teachers is taking some time off for a little putt-putt golf. The 15th hole at the Hole-In-One Putt-Putt Golf Course has a large metal rim that putters must use to guide their ball towards the hole. Mr. S guides a golf ball around the metal rim When the ball leaves the rim, which path (1, 2, or 3) will the golf ball follow?

1

2

3

None of the above.

The answer is 2. Once leaving the rim, the ball will follow an "inertial path" (i.e., a straight line). At the instant shown in the diagram, the ball is moving to the right; once leaving the rim, there is no more unbalanced forces to change its state of motion. Paths 1 and 3 both show the ball continually changing its direction once leaving the rim.

Explanation

The answer is 2. Once leaving the rim, the ball will follow an "inertial path" (i.e., a straight line). At the instant shown in the diagram, the ball is moving to the right; once leaving the rim, there is no more unbalanced forces to change its state of motion. Paths 1 and 3 both show the ball continually changing its direction once leaving the rim.

7. Fred spends most Sunday afternoons at rest on the sofa, watching pro football games and consuming large quantities of food. If he does this for several months what effect (if any) does this practice have upon his inertia?

Fred's inertia stays the same!

Fred's inertia will decrease!

Fred's inertia will increase!

None of the above.

Fred's inertia will increase!

Fred will increase his mass if he makes a habit of this. And if his mass increases, then his inertia increases.

Explanation

Fred's inertia will increase!

Fred will increase his mass if he makes a habit of this. And if his mass increases, then his inertia increases.

8. A bowling ball is rolling across the floor with a speed of 4 m/s. How much net force is required to keep the object moving at this speed and in this direction (assume no friction or gravity is present)?

0 N

1 N

10 N

None of the above.

An object in motion will maintain its state of motion. The presence of an unbalanced force changes the velocity of the object.

Explanation

An object in motion will maintain its state of motion. The presence of an unbalanced force changes the velocity of the object.

9. ______________ states that "An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force."

Newton's First Law of Motion, also known as the law of inertia, states that an object at rest will remain at rest, and an object in motion will continue moving at a constant velocity in a straight line unless acted upon by an external force. This means that objects tend to maintain their state of motion unless an unbalanced force is applied to change their speed or direction. In other words, if no force is acting on an object, it will either remain at rest or continue moving with the same speed and direction.

Explanation

Newton's First Law of Motion, also known as the law of inertia, states that an object at rest will remain at rest, and an object in motion will continue moving at a constant velocity in a straight line unless acted upon by an external force. This means that objects tend to maintain their state of motion unless an unbalanced force is applied to change their speed or direction. In other words, if no force is acting on an object, it will either remain at rest or continue moving with the same speed and direction.

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10. If the forces acting upon an object are balanced, then the object

Must not be moving.

Must be moving with a constant velocity.

Must not be accelerating.

None of these.

The answer could be A (but does not have to be A) and it could be B (but does not have to be B). An object having balanced forces definitely cannot be accelerating. This means that it could be at rest and staying at rest (one option) or could be in motion at constant velocity (a second option). Either way, it definitely is not accelerating - choice C of your four choices.

Explanation

The answer could be A (but does not have to be A) and it could be B (but does not have to be B). An object having balanced forces definitely cannot be accelerating. This means that it could be at rest and staying at rest (one option) or could be in motion at constant velocity (a second option). Either way, it definitely is not accelerating - choice C of your four choices.