Question

11. When the acceleration of particle is positive
and is increasing, then its velocity must be
positive.​

Answer 1

Answer:

Not necessary

False!!!

Explanation:

Negative acceleration means the final velocity is less than initial velocity

Negative sign of velocity denotes it's direction thus acceleration can be negative even when velocity of an object is negative.

Answer 2

It must be speeding up.

Given acceleration a>0,

=> v=u+at

Assume initial velocity u=0=>v=at, so speed must be speeding up because acceleration is positive and time is always positive.