Question

please help me solve this..
A body of mass 2 kg at O has an initial velocity of 3 ms^-1 along OE and it is subjected to a force of 4 Newton(N) in a direction perpendicular to OE . The distance of body from O after 4 sec will be
a. 12 m
b. 20 m

Answer 1

the above answer is wrong.
Split up the initial direction as x and the perpendicular direction as y

Now velocity along x is constant since force is perpendicular. so distance along x = v_x*t=12m

Velocity along y is not constant and is equal to 2t since acceleration = F/m = 4n/2kg=2m/s^2
Then the displacement = t^2= 16
Now use pythagorean theorem to compute total displacement d^2=12^2+16^2=20^2
so d=20

Answer 2

thanks a lot..can u pls tell y v have 2 take t^2
& d^2..