Kinematics Question 692
Question: A stone is projected from the ground with velocity $ 25m/s $ . Two seconds later, it just clears a wall 5 m high. The angle of projection of the stone is $ (g=10m/{{\sec }^{2}}) $
Options:
A) $ 30^{o} $
B) $ 45^{o} $
C) $ {{50.2}^{o}} $
D) $ 60^{o} $
Show Answer
Answer:
Correct Answer: A
Solution:
[a] For vertical upward motion $ h=ut-\frac{1}{2}gt^{2} $
$ 5=(25\sin \theta )\times 2-\frac{1}{2}\times 10\times {{(2)}^{2}} $
$ \Rightarrow 25=50\sin \theta \Rightarrow \sin \theta =\frac{1}{2}\Rightarrow \theta =30{}^\circ $
