Question

A big boat and a small boat are moving at the same speed and begin slowing down to a stop. The big boat takes less time to stop. Which boat has greater average acceleration (magnitude) during this stop?

• A. the big boat
• B. the small boat
• C. The boat have the same average acceleration
• D. The boat's relative acceleration cannot be determined.
• E. The boat are not accelerating.

Answer 1

The correct option is A the big boat

Let $u$ be the initial velocity of both the boats , as both boats stop at last therefore their final velocity $v$ will be zero ,

now by $v=u-at$ , $a$ is taken negative because boats are slowing down so it is deceleration ,

for big boat $v=u-a_1{t}_1$ ,

or $a_1=(u-v)/t_1=u/t_1$ , as $v=0$ ,

where $t_1=$ time taken by big boat to stop ,

similarly for small boat $a_2=u/t_2$ ,

now given that $t_1<t_2$ therefore $a_1>a_2$

acceleration of the big boat is larger than small one .