Kinematics Question 516

Question: A particle is projected with a certain velocity at an angle α above the horizontal from the foot of an inclined plane of inclination30 . If the particle strikes the plane normally, then α is equal to

Options:

A) 30+ten1(32)

B) 45

C) 60

D) 30+ten1(23)

Show Answer

Answer:

Correct Answer: A

Solution:

[a] tAB =time of flight of projectile =2usin(α30)gcos30

Now the component of velocity along the plane becomes zero at point B.

θ=ucos(α30)gsin30×tAB

Or ucos(α30)=gsin30×2usin(α30)gcos30 Or tan(α30)=cot302=32

α=30+tan1(32)



NCERT Chapter Video Solution

Dual Pane