Ball mass 10g dropped from height 2m to a horizontal ground,it then bounced back to height 1.5m . determine energy loss when it contact with ground and coefficient of restrictions of ball and ground?

To determine the energy loss when the ball contacts the ground, we can use the principle of conservation of energy.

The potential energy of the ball when it is dropped from a height of 2m is given by:

PE_initial = mgh
PE_initial = 0.01kg * 9.81m/s^2 * 2m
PE_initial = 0.1962 J

When the ball bounces back to a height of 1.5m, its potential energy is given by:

PE_final = mgh
PE_final = 0.01kg * 9.81m/s^2 * 1.5m
PE_final = 0.14715 J

The energy loss when the ball contacts the ground is the difference between the initial potential energy and the final potential energy:

Energy loss = PE_initial - PE_final
Energy loss = 0.1962 J - 0.14715 J
Energy loss = 0.04905 J

Next, we can determine the coefficient of restitution (COR) of the ball and the ground. The coefficient of restitution is a measure of how "bouncy" a collision is. It is defined as the ratio of the relative velocity of separation to the relative velocity of approach.

The relative velocity of approach (Va) is the velocity of the ball just before it contacts the ground. Since the ball is dropped from rest, Va = 0 m/s.

The relative velocity of separation (Vb) is the velocity of the ball just after it bounces back. We can use the principle of conservation of energy to determine Vb:

KE_initial = PE_final
0.5mv^2 = mgh
0.5v^2 = gh
v^2 = 2gh
v = sqrt(2 * 9.81m/s^2 * 1.5m)
v = 5.42 m/s

Now, we can calculate the coefficient of restitution (COR) using the formula:

COR = Vb / Va
COR = 5.42 m/s / 0 m/s
COR = Infinity

This result indicates that the collision between the ball and the ground is perfectly elastic, meaning that there is no energy loss during the collision. However, in reality, there will always be some energy loss due to factors such as air resistance, deformation of the ball, and sound production.

Energy Loss

The energy loss is the difference between the total energy just before the ball hits the ground and the total energy just after it bounces back.

Total Energy Before Contact:

```
E_before = mgh = (0.01 kg)(9.8 m/s²)(2 m) = 0.196 J
```

Total Energy After Bounce:

```
E_after = mgh = (0.01 kg)(9.8 m/s²)(1.5 m) = 0.147 J
```

Energy Loss:

```
E_loss = E_before - E_after = 0.196 J - 0.147 J = 0.049 J
```

Coefficient of Restitution

The coefficient of restitution is a measure of how elastic the collision is. It is defined as the ratio of the relative velocity after the collision to the relative velocity before the collision.

In this case, the relative velocity before the collision is equal to the initial velocity of the ball, which is:

```
v_before = √(2gh) = √(2(9.8 m/s²)(2 m)) = 6.26 m/s
```

The relative velocity after the collision is equal to the velocity of the ball just after it bounces back, which is:

```
v_after = √(2gh) = √(2(9.8 m/s²)(1.5 m)) = 5.97 m/s
```

Therefore, the coefficient of restitution is:

```
e = v_after / v_before = 5.97 m/s / 6.26 m/s = 0.954
```

This value is relatively high, indicating that the collision is fairly elastic.