A 0.3 kg tennis ball is travelling west with a speed of 4 m/s and bounces off a wall. After bouncing, the ball is travelling east at 2 m/s. The tennis ball was in contact with the wall for 0.004 seconds a) what is the initial and final momentum of the ball?
b) what is the direction and magnitude of the force the ball experienced due to the wall?
c) What is the direction and magnitude of th force the wall experienced due to the ball?

C_d = 0.942

Explanation:

Let's first calculate the angle of inclination.

Formula is;

tan θ = (%slope)

% Slope is given as 12%

Thus;

θ = tan^(-1) (12/100)

θ = 6.843°

Let's now calculate the force due to the weight of the rider and bike combined from;

F = mg sin θ

We are given; m = 100 kg.

Thus;

F = 100 × 9.81 × sin 6.843

F = 116.885 N

The drag force will also be the same as the force due to the weight of the body. Thus;

Drag force; F = C_d(½ρu²A)

Where;

C_d is drag coefficient

ρ is density

U is terminal speed

A is area

We are given;

A = 0.9 m²

U = 15 m/s

From online tables, density of air is approximately 1.225 kg/m³

Thus;

116.885 = C_d(½ × 1.225 × 15² × 0.9)

116.885 = 124.03125C_d

C_d = 116.885/124.03125

C_d = 0.942