Answer:
a) 482N Upward
b) 482N Downward
Explanation:
According to Newton's second law:
[tex]\sum F=m.a\\F_p-m.g=m.a\\F_p=m(g+a)\\m=\frac{F}{g}\\m=\frac{718N}{9.81m/s^2}\\m=73.2kg\\\\F_p=73.2kg(9.81m/s^2-3.22m/s^2)\\F_p=482N[/tex]
We substract the acceleration of 3.22m/s^2 because it is going downwards.
The direction of the force is upward because it is opposite to the movement, that's why the acceleration is smaller than the gravity's acceleration.
According to Newton's third law, The force of the firefighter must be the same but in the opposite direction, so:
[tex]F_f=482N\\[/tex]
going downward.
