Answer:
[tex]10500\; {\rm N}[/tex], assuming that the motion is at constant speed.
Explanation:
To find the work that was done, multiply power by time:
[tex]\begin{aligned}(\text{work}) &= (\text{power})\, (\text{time}) \\ &= (3500\; {\rm W}) \, (3\; {\rm s}) \\ &= 10500\; {\rm J}\end{aligned}[/tex].
Assume that the computer was lifted at a constant speed. The force that lifted the computer would be constant and equal to opposite of the weight of the computer.
Since force is constant, divide work by displacement to find this force:
[tex]\begin{aligned}(\text{force}) &= \frac{(\text{work})}{(\text{displacement})} \\ &= \frac{10500\; {\rm J}}{1\; {\rm m}} = 10500\; {\rm N}\end{aligned}[/tex].
In other words, the magnitude of the force that lifted the computer is [tex]10500\; {\rm N}[/tex]. Under the assumption that the computer was lifted at constant velocity, the weight of the computer would have the same magnitude, [tex]10500\; {\rm N}\![/tex].
