A 240 g ball is dropped from a height of 2.1 m, bounces on a hard floor, and rebounds to a height of 1.6 m. The figure shows the impulse received from the floor. What maximum force does the floor exert on the ball?

impulse =.005*Fmax

FΔt=mΔv-->F=m (Δv) / (Δt)

We can find the speed by calculating the potential energy and converting it to kinetic energy. Ep = Ek - - >mgh=m v^2 / 2

v = (√ 2gh) = (√ 2∗9.81∗2.1) ≈6.42m/s

so then F=.240∗6.42/0.005=308 N (we know the time because of the above mentioned impulse equation.)