Question

2.
Which of the following statements is true for a moving body?
A) If its speed changes, its velocity must change and it must have some
acceleration
B) If its velocity changes, ils speed must change and it must have some
acceleration.
C) If its velocity changes, its speed may or may not change, and it must have
some acceleration
D) If its speed changes but direction of motion does not change, its velocity
may remain constant.

And also explain.​

Answer 1

A) If its speed changes, its velocity must change and it must have some

acceleration.

Because, with the increasing or decreasing of speed the velocity must be changed as velocity is directly proportional to speed and when there is change in velocity then there is change in magnitude too so, there must be positive or negative acceleration.