Kinematics Question 512
Question: A man standing on the roof of a house of height $ h $ throws one particle vertically downwards and another particle horizontally with the same velocity u. The ratio of their velocities when they reach the earth’s surface will be
Options:
A) $ \sqrt{2gh+{u _{^{^{{}}}}}^{2}}:u $
B) $ 1:2 $
C) $ 1:1 $
D) $ \sqrt{2gh+u^{2}}:\sqrt{2gh} $
Show Answer
Answer:
Correct Answer: C
Solution:
[c] When particle is thrown in vertical downward direction with velocity u, then the final velocity at the ground level it’s $ v^{2}=u^{2}+2gh $
$ \therefore v=\sqrt{u^{2}+2gh} $
Another particle is thrown horizontally with same velocity then at the surface of earth.
Horizontal component of velocity $ v _{x}=u $
Therefore, resultant velocity, $ v=\sqrt{u^{2}+2gh} $
For both the particles, final velocities when they reach the earth’ surface are equal.
