a net force of 5 newton moves a 2kg object a distances of 3 m in 3 s.how much work is done on object?

Question

15j
10j
1j
30 j

Answer 1

If its a simple question the answer is clearly 15 J
but if we consider the resistive force acting it would be complicated
The answer then can be done like this
let the resistive force(of course in direction opposite to F=5N) be x
Net force is 5-x
acc. req. to move 3m in 3 s is
3=1/2*a*3^2
or a=2/3 m/s^2
Therefore net force on the body is ma
=4/3 N
therefore 5-x=4/3
or x=11/3N
Now work done by F is 15J
and work done by x is -11J(as the force is resistive)
Therefore net work done is 4J

Answer 2

work=force times distance
work=5*3
work=15

Answer 3

W = Fx

W = (5N)(3m)
W = 15J