Answer:
[tex]32\; {\rm J}[/tex], Assuming the external force is the only force on this object, such that the acceleration of this object would be in the direction of the force.
Explanation:
The work that the force did on the object is equal to the product of:
In this question, the magnitude of the force is given. The displacement of the object in the direction of this force needs to be found.
Acceleration of this object is constant and (by assumption) in the direction of the force. Given the value of initial velocity [tex]u = 0\; {\rm m\cdot s^{-1}}[/tex], acceleration [tex]a = 0.1\; {\rm m\cdot s^{-2}}[/tex], and duration [tex]t = 4\; {\rm s}[/tex], apply the following SUVAT equation to find displacement in the direction of this force:
[tex]\begin{aligned} x &= \frac{1}{2}\, a\, t^{2} + u\, t = 0.8\; {\rm m}\end{aligned}[/tex].
Hence, the displacement of this object would be [tex]0.8\; {\rm m}[/tex] in the direction of this force. The work that this force did on the object would be:
[tex](40\; {\rm N})\, (0.8\; {\rm m}) = 32\; {\rm J}[/tex].
