A tennis ball of 60g is dropped from a height of 2.0m,It rebounds but loses 25% of its kintic energy as thermal energy.Ignoring air resistance,calculate

incomplete question, repeated later

a car had a negative accelerations of 5.6m/s^2 for 2.5 seconds. If the initial velocity of the car was 28m/s [E] (let east be positive), what was the car's final velocity?

To calculate the rebound height of the tennis ball, we need to use the principle of conservation of mechanical energy. The potential energy at the highest point is converted into kinetic energy at the lowest point. However, since the ball loses 25% of its kinetic energy as thermal energy during the rebound, we need to take that into account.

First, let's calculate the initial potential energy of the tennis ball at the highest point:
Potential energy (PE) = mass (m) x gravitational acceleration (g) x height (h)
PE = 0.06 kg x 9.8 m/s^2 x 2 m
PE = 1.176 Joules

Next, let's calculate the initial kinetic energy of the tennis ball at the lowest point:
Kinetic energy (KE) = 0.5 x mass (m) x velocity^2 (v^2)
Since the ball is dropped from rest, the initial velocity (v) is 0.
KE = 0.5 x 0.06 kg x (0 m/s)^2
KE = 0 Joules

Now, let's calculate the energy lost as thermal energy during the rebound:
Energy lost = 25% of initial kinetic energy
Energy lost = 0.25 x KE
Energy lost = 0.25 x 0 Joules
Energy lost = 0 Joules

Since the total mechanical energy is conserved, the final mechanical energy will be equal to the initial mechanical energy. Therefore, the final potential energy will be equal to the initial potential energy:

Final potential energy = Initial potential energy
Final potential energy = 1.176 Joules

Now, let's calculate the rebound height using the final potential energy:
Final potential energy (PE) = mass (m) x gravitational acceleration (g) x rebound height (h')
h' = PE / (m x g)
h' = 1.176 Joules / (0.06 kg x 9.8 m/s^2)
h' ≈ 2 m

Therefore, the rebound height of the tennis ball is approximately 2.0 meters.