An object with mass ( 5 ~kg ) is acted upon by a force, ( F =(-3 i +4 j ) N ). If its initial velocity at ( t =0 ) is ( v =(6 i -12 j ) ms ⁻¹ ), the time at which it will just have a velocity along ( y )-axis is

Step-by-step solution

(D) F =(-3 i +4 j )m a =(-3 i +4 j )M=5 ~kg a = ( -3 5 i + 4 5 j ) a =a_ x i +a_ y j a_ x = -3 5 at t =0 V ₀=(6 i -12 j ) (V_ o x i -V_ o y j )V_ o x =6 For the body to have velocity along y-axis only, x-component of velocity should be zero i.e., V_ x =0V_ x =V_ o x +a_ x t0=6+ ( -3 5 ) t6= 3 5 tt= 6 5 3 =10 s OR A= F m = (- 3 5 i + 4 5 j ) u =(6 i -12 j ) m s⁻¹ v = u + at. 1 j =(6 i -12 j )+ (- 3 5 i + 4 5 j ) t