First Law of Motion

Q. When two identical balls $b_1$ and $b_2$, which have equal masses are moving with velocities, $V$ and $2V$ respectively, the ratio of inertia and momentum of $b_1$ to $b_2$ are:

1. $2:1$ and $1:2$
2. $1:1$ and $1:2$
3. $1:1$ and $1:1$
4. $1:1$ and $2:1$

Q. Which of the following statements are correct?

1. If a body is in motion, then no force is acting on it.
2. If a body remains at rest, then the net force acting on it must be zero.
3. If the acceleration of a body is zero, then the body is at rest.
4. If a body is at rest, there must be some non-zero force to keep it at rest.

Q. An object of mass $2kg$ is sliding with a constant velocity of $4m{s}^{-1}$ on a frictionless horizontal table. The force required to keep the object moving with the same velocity is:

1. $32N$
2. $0$
3. $2N$
4. $8N$

Q.

If a body is moving in a straight line at a constant velocity, then no forces are acting on the body.

1. False

2. True

Q.

Which of the following statements are true in the real world scenario?

Statement 1: A uniform motion requires no net force.

Statement 2: In practical situation friction force is always zero.

Statement 3: Friction force acts opposite to the direction of relative motion.

Statement 4: Frictional force can be minimized by using rough surface.

1. All statements are true except statement 2.

2. Only statements 1 and 3 are correct.

3. Only statement 2 and 4 are true.

4. All statements are true.

Q. In the case of a moving body, force is not needed to:

1. increase the speed of the body
2. decrease the momentum of the body
3. change the direction of motion
4. keep the body in uniform velocity

Q.

The importance of Newton's first law of motion is that:

1. it mentions force

2. it defines inertia

3. it defines momentum

4. it defines acceleration

Q. A marble is moving on a perfectly smooth horizontal surface with uniform speed and no external force. Choose the correct observation.

1. It will stop after some time.

2. It will start accelerating.

3. It will keep moving forever at constant speed.

4. It experience high frictional force

Q. An object of mass $2kg$ is sliding with a constant velocity of $4m{s}^{-1}$ on a frictionless horizontal table. The force required to keep the object moving with the same velocity is:

1. $8N$
2. $32N$
3. $0$
4. $2N$

Q. Change in speed or the direction of speed of an object would continue as long as unbalanced forces are applied on it.

1. True

2. False