Rain is falling with speed 12√2 m/s at an angle 45° with vertical line. A man in a glider going at a speed of v at an angle of 37° with respect to ground, find the speed 5x (in m/s) of glider so that rain appears to him falling vertically. Consider motion of glider and rain drops in same vertical plane. Find x
Physics · Mixed Chapter
JEE Mains

Question

Rain is falling with speed 12√2 m/s at an angle 45° with vertical line. A man in a glider going at a speed of v at an angle of 37° with respect to ground, find the speed 5x (in m/s) of glider so that rain appears to him falling vertically. Consider motion of glider and rain drops in same vertical plane. Find x

Physics · Mixed Chapter

G1 Physics · Accepted Answer

Step 1: Rain speed is 12√2 m/s at 45° to vertical, so its horizontal component is vᵣₓ=12√2 sin45°=12 m/s in the direction shown. Step 2: For rain to appear vertically falling to the moving glider, horizontal relative velocity must vanish: speed of the glider cos37°=12. Step 3: cos37°=4/5 gives speed of the glider=12×5/4=15 m/s. Step 4: Given glider speed is 5x m/s, 5x=15 ⇒x=3. Answer: 3.