Average force on a bouncing ball

Classical Mechanics

A 1 $\text{kg}$ basketball is dropped from a height of 5 $\text{m}$ , bounces off the ground, and returns to a maximum height of 1.8 $\text{m}$ . Find the magnitude of the average force (in $\text{N}$ ) between the ball and the ground if the ball is in contact with the ground for 0.1 s. (Use $g=10 \text{m}/\text{s}^2$ for the acceleration due to gravity.)