I found some missing information about this problem online. We are given the force:
[tex] F = F =(-7.50N)i +(3.00N)j[/tex]
Power is defined as the rate of doing work.
This is the formula:
[tex]P= \frac{dW}{dt} [/tex]
Where P is power, W is work.
Work is defined as:
[tex]W=F\cdot r[/tex]
F is the force and r is the displacement.
If we assume that force is not changing (it's constant) with time we get:
[tex]P= \frac{dW}{dt}=F \frac{dr}{dt}=F\cdot v [/tex]
Keep in mind that both force and velocity are vectors, so we have to multiply each component separately.
Finally, we get:
[tex]P=F_i\cdot v_i+F_j\cdot v_j=(-7.50N)(3.40\frac{m}{s})+(3.00N)(2.20\frac{m}{s})=
-18.9 W[/tex]
