Question

Which of the following is/are true?

(i) if object's acceleration is constant then it must move in a straight line

(ii) if object's acceleration is zero, then its speed must remain constant

(iii) if an object's speed remains constant then its acceleration must be zero

• A. (i) and (ii) only
• B. (i) and (iii) only
• C. (ii) only
• D. (iii) only

Answer 1

The correct option is C

(ii) only

Statement (i) is false because in a projectile motion, acceleration is constant but object does not move in straight line.

Statement (iii) is false as in circular motion speed is constant but the acceleration is not zero.

Only statement (ii) is true because acceleration zero implies that there is no change in speed.