Question

Multiple Correct Answers Type:
Which of the following statements is/are correct?

• A. If the velocity of a body changes, it must have some acceleration.
• B. If the speed of a body changes, it must have some acceleration.
• C. If the body has acceleration, its speed must change.
• D. If the body has acceleration, its speed may change.

Answer 1

Answer: (A), (B), (D)

The correct options are
A If the velocity of a body changes, it must have some acceleration.
B If the speed of a body changes, it must have some acceleration.
D If the body has acceleration, its speed may change.

Acceleration is defined as the rate of change of velocity $(\overrightarrow{a}=\frac{\Delta \overrightarrow{v}}{\Delta \overrightarrow{t}})$

Thus if velocity changes it must have some acceleration.

Now, velocity $\left(\overrightarrow{v}\right)$ is a vector. and then has two components

magnitude (which is numerically speed) and direction.

In ease speed changes,the velocity vector changes, evading to accln.

However. if accln. is there due to change is direction of velocity

vector only (as if in circular motion), the speed doesn't

mcenaring change.