Question

Which of the following example shows an object does not change its magnitude of velocity but only its direction of motion.

• A. Parachutist bailing out of the airplane
• B. The motion of a body along a circular path.
• C. A body moving up against gravity.
• D. A car moving with uniform velocity in a straight line

Answer 1

The correct option is B

The motion of a body along a circular path.

Step 1: Explanation for the correct answer

b)The motion of a body along a circular path.

1. When a body moves along a circular path with constant velocity- then motion is said to be uniform circular motion.
2. Here the direction of motion continuously changes as the object rotates in a circle.
3. So, in this case, the magnitude of velocity does not change but the direction of motion changes continuously.

Step 2: Explanation for the wrong answer

a) Parachutist bailing out of the airplane.

1. When a person jumps out of the plane using a parachute, then that person is under gravity.
2. The velocity of the parachute is not constant,
3. The direction of the parachute is towards the earth because of gravity.

c)A body moving up against gravity.

1. In this case velocity of the motion continuously decreases, at the maximum height velocity becomes zero.
2. After reaching maximum height the direction of motion gets reversed.

d)A car moving with uniform velocity in a straight line

1. In this case velocity as well as direction is constant.

Hence,

option (b) is correct.