A small ball is dropped from a balloon moving vertically up at a speed 10 m/s when the balloon is at a height 15 m from the ground. Neglect air friction and take g = 10m/s². Which of the following is not a suitable to the present situation ?

see full answer

Your Exam Success, Personally Taken Care Of

1:1 expert mentors customize learning to your strength and weaknesses – so you score higher in school , IIT JEE and NEET entrance exams.

An Intiative by Sri Chaitanya

The ball covers a distance of 25 m

The ball moves up at a speed 10 m/s at an instant when it is dropped from the balloon

The ball reaches the ground in 3 s

The magnitude of average velocity of the ball is 8.33 m/s.

answer is A.

(Unlock A.I Detailed Solution for FREE)

Best Courses for You

JEE

NEET

Foundation JEE

Foundation NEET

CBSE

Detailed Solution

The maximum height Reached by the ball after through from the balloon
$h = \frac{u^{2}}{2 g} = \frac{100}{2 \times 10} = 5 m$
Distance travelled by the ball = 5+5+15 = 25m
$\begin{array}{l} - h = ut - \frac{1}{2} {gt}^{2} \\ - 15 = 10 t - \frac{1}{2} \times 10 t^{2} \\ 5 t^{2} - 10 t - 15 = 0 \\ t^{2} - 2 t - 3 = 0 \\ t^{2} - 3 t + t - 3 = 0 \\ t (t - 3) + 1 (t - 3) = 0 \\ (t + 1) (t - 3) = 0 \\ t = 3, - 1 \end{array}$