Manipal MET2013PhysicsMotion in Two Dimensions
A man crosses a 320 m wide river perpendicular to the current in 4 min . If in still water he can swim with a speed 5 / 3 times that of the current, then the speed of the current, in mm ⁻¹ in is
Options
- A30
- B40
- C50
- D60
Correct answer
D. 60
Step-by-step solution
v_r^2=v_m^2-v^2v= 320 4 ~m / min =80 ~m / min aligned & v_m= 5 3 v_r & v_r^2=t 5 3 (v_r )^2-(80)^2 aligned 16 9 v_r^2=(80)^2u^2, u₀ form canours linear