A 90kg bungee jumper jumps from a bridge 40m above the river. The bungee cord has an unstretched length of 18m and has a stiffness of 200N/m. Solve for the maximum force, in N, that the cord exerts on the jumper. Round your answer to 2 decimal places.

In the very Dutch sport of Fierljeppen, athletes run up to a long pole and then use it to vault across a canal as shown in (Figure 1). At the very top of his arc, a 70 kg vaulter is moving at 2.9 m/s and is 5.5 m from the bottom end of the pole. What is the magnitude of the vertical force that the pole exerts on the vaulter? Express your answer with the appropriate units.

please answer only using algebra, no calculus

A 36 kg child stands on a roof, 29 m above a trampoline held by firemen.  The trampoline has a stiffness of 809 N/m.  To save himself from the flames, the child musters the courage to jump, and lands on the trampoline.  Calculate the maximum compression of the trampoline, in m. (Please answer to the fourth decimal place - i.e 14.3225)

A daredevil wishes to bungee-jump from a hot-air balloon 64.5 m above a carnival midway. He will use a piece of uniform elastic cord tied to a harness around his body to stop his fall at a point 12.0 m above the ground. Model his body as a particle and the cord as having negligible mass and a tension force described by Hooke's force law. In a preliminary test, hanging at rest from a 5.00-m length of the cord, the jumper finds that his body weight stretches it by 1.65 m. He will drop from rest at the point where the top end of a longer section of the cord is attached to the stationary balloon. (a) What length of cord should he use? m(b) What maximum acceleration will he experience? m/s2