Rain falls at 20 m s⁻¹ at 30° to the vertical, driven along the direction of a train moving at 108 km h⁻¹. Find the apparent speed of rain for a passenger in the train.
Options

Question

Rain falls at 20 m s⁻¹ at 30° to the vertical, driven along the direction of a train moving at 108 km h⁻¹. Find the apparent speed of rain for a passenger in the train.

G1 Physics · Accepted Answer

Rain components: horizontal=10 m s⁻¹, vertical=10√3 m s⁻¹. Train speed=30 m s⁻¹ in the same horizontal direction. Relative horizontal component=-20 m s⁻¹. Magnitude=√(400+300)=10√7 m s⁻¹. Option B.