A force of (2.6 i +1.6 j ) N acts on a body of mass 2 ~kg . If the velocity of the body at time, t=0 is (3.6 i -4.8 j ) ms ⁻¹ , the time at which the body will just have a velocity along x -axis only is

Step-by-step solution

Given, force acts on a body, F =(2.6 i +1.6 j ) N mass of a body, m=2 ~kg At t=0 , velocity of the body, v=(3.6 i -4.8 j ) m / s We know that, Force = Mass Acceleration or aligned & F =m a & a = F m aligned or a = (2.6 i +1.6 j ) 2 or a =(1.3 i +0.8 j ) m / s ^2 Now, the velocity vector, d v d t = a d v = a d t aligned & or v =(1.3 i +0.8 j ) t+c & at t=0, c= v =(3.6 i -4.8 j ) ms ⁻¹ & v =(3.6+1.3 t) i + ⁻(-4.8+0.8 t) j m / s & v_y=0 (because body will just have a velocity & along x -axis.) & -4.8+0.8 t=0 & 0.8 t=4