A body mass `2kg` has an initial velocity of 3 metre//sec along OE and it is subject to a force of `4N` in a direction perpendicular to OE. The distance of body from `O` after 4 sec will be:

Options

A. 12 m
B. 20 m
C. 8 m
D. 48 m

Answer

B

Explanation

Displacement of body in 4 sec
along OE
`s_x=v_xt=3xx4=12m`
Force along OF (perpendicular to OE)`=4N`
`a_y=(F)/(m)=(4)/(2)=2(m)/(s^2)`
Displacement of body in 4 sec along OF
`impliess_y=u_yt+(1)/(2)a_yt^2=(1)/(2)xx2xx(4)^2=16m`
Net displacement `s=sqrt(s_x^2+s_y^2)=sqrt((12)^2+(16)^2)=20m`