Complete the sentences and explain them.

A. The minimum distance between the start and finish points of the motion of an object is called the ______ of the object.

B. Deceleration is ______ acceleration

C. When an object is in uniform circular motion, its ______changes at every point.

D. During collision ______remains constant.

E. The working of a rocket depends on Newton’s ______ law of motion.

A. The minimum distance between the start and finish points of the motion of an object is called the displacement of the object.

Explanation:

As seen in the given figure,

The distance is not same as displacement. In fact, the displacement is the shortest distance between two given points.

B. Deceleration is negative acceleration.

Explanation:

Acceleration means increase in velocity. And, for decrease in velocity we have another term called “negative acceleration or deceleration”.

The figure shows the velocity time graph of an object:

C. When an object is in uniform circular motion, its velocity changes at every point.

Explanation:

In uniform circular motion, the speed of the object is same. Since, it direction is changing at every instant, hence its velocity changes. Because, velocity is speed with direction.

The object in uniform circular motion is shown here:

Here, the magnitude of both velocities is same.

D. During collision total momentum remains constant.

Explanation:

During collision the total momentum, remains the same.

The figure shows two objects here before & after collision:

E. The working of a rocket depends on Newton’s third law of motion.

Explanation: According to Newton’s third law of motion, every action has an equal and opposite reaction.

In a rocket, the burnt fuel releases gases, which push the rocket upwards. The direction of forces is given in the figure below: