Question
Physics Question on Motion in a plane
A man is walking due east at the rate of 2 km/h. The rain appears to him to come down vertically at the rate of 2 km/h. The actual velocity and direction of rainfall with the vertical respectively are
A
22km/h,450
B
21km/h,300
C
2km/h,00
D
1km/h,900
Answer
22km/h,450
Explanation
Solution
Velocity of man, vm=2km/h Velocity of rain, vr=2km/h Then actual velocity vrm=vm2+vr2 =(2)2+(2)2 =4+4=22km/h The direction of rainfall with the vertical sinθ=vrmvr =222=21 θ=sin−1(21) θ=45o