Answer:
0.59 seconds
Step-by-step explanation:
To find the time it takes for a tennis ball to reach the ground and bounce back to a height of 7 meters, we need to use the formula for the time it takes an object to fall to the ground.
The formula for the time it takes an object to fall to the ground is given by:
t = sqrt(2 * d / g)
where t is the time it takes the object to fall, d is the distance the object falls, and g is the acceleration due to gravity.
In this case, we are given that the height from which the tennis ball is dropped is 3 meters, the height to which the ball bounces is 7 meters, and the acceleration due to gravity is 9.8 m/s^2. We can use these values to solve for the time it takes for the ball to reach the ground and bounce back to a height of 7 meters.
First, we need to calculate the distance the ball falls. The distance the ball falls is equal to the difference between the height from which the ball is dropped and the height to which the ball bounces:
d = H1 - H2
d = 3 - 7
d = -4
Next, we can use the formula for the time it takes an object to fall to the ground to solve for the time it takes for the ball to reach the ground and bounce back to a height of 7 meters:
t = sqrt(2 * d / g)
t = sqrt(2 * -4 / 9.8)
t = 0.59 seconds
Therefore, it takes 0.59 seconds for the tennis ball to reach the ground and bounce back to a height of 7 meters.