From a balloon moving upwards with a velocity of $$12\,m{s^{ - 1}},$$ a packet is released when it is at a height of $$65\,m$$ from the ground. The time taken by it to reach the ground is
$$\left( {g = 10\,m{s^{ - 2}}} \right)$$
A.
$$5\,s$$
B.
$$8\,s$$
C.
$$4\,s$$
D.
$$7\,s$$
Answer :
$$5\,s$$
Solution :
$$s = ut + \frac{1}{2}a{t^2}$$
$$ - 65 = 12t - 5{t^2}$$ on solving we get, $$t = 5\,s$$
Releted MCQ Question on Basic Physics >> Kinematics
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