A spot light S rotates in a horizontal plane with a constant angular velocity of 0.1 rad/s. The spot of light P moves along the wall at a distance 3m. What is the velocity of the spot P when θ=45o?
Linear velocity,v=wrsinθ
If d is the distance from the spot light to wall
r=dcosθ
=3cos(45∘)
velocity of the spot,v=lorsinθ=0.1×3cos45∘sin45∘
=0.6ms−1