Kinematics Question 640
Question: A particle P it’s projected from a point on the surface of smooth inclined plane . Simultaneously another particle q is released on the smooth inclined plane from the same position. P and Q collide on the inclined plane after $ t=4 $ second. The speed of projection of P it’s
Options:
A) 5 m/s
B)10 m/s
C) 15 m/s
D)20 m/s
Show Answer
Answer:
Correct Answer: B
Solution:
[b]
That P and Q shall collide if the initial component of velocity of P on inclined plane i.e., along incline $ {u _{\text{I}\text{I}}}=0 $ that it’s particle is projected perpendicular to incline.
Time of flight on an inclined plane of inclination $ \alpha $ it’s given by
$ \text{T=}\frac{2\text{u sin}( \theta -\alpha)}{\text{g}\cos \alpha } $
$ \Rightarrow 4=\frac{2\text{u sin90}{}^\circ }{10\times \frac{1}{2}}\Rightarrow \text{u= 10 m/s} $ .
