Answer:
The time taken for the ball to fly up in the air and back down again is 3.058 seconds.
Explanation:
Since the ball ends up at the same vertical distance ( on the ground) as it was at the start of its motion, we can set the total displacement of the ball equal to 0.
Thus, this problem can be simply solved by the following equation of motion:

Here, s = total change in distance = 0 m
u = initial speed = 15 m/s
a = acceleration due to gravity = -9.81 m/s^2
t = time (to be found)
Substituting these values in the equation we get:



t = 3.058 seconds
So, the time taken for the ball to fly up in the air and back down again is 3.058 seconds.
Answer:
Mechanical energy
Explanation:
Mechanical energy is needed for movement of objects. Muscles convert chemical energy provided by the rest of the body to allow movement.
Answer:
By Applying pressure to the brakes
Explanation:
Driving cars through deep water that is more than 10cm can make the cars to float. Most modern cars are usually water- tight so they can start to float through water that is about 30cm deep, fast moving water is very powerful so one needs to be very careful when driving.
If the brakes are wet test them by pressing or tapping on them gently.
You can as well dry brakes by driving in low gear and applying pressure to the brakes.
Stars form from an accumulation of gas and dust, which collapses due to gravity and starts to form stars. The process of star formation takes around a million years from the time the initial gas cloud starts to collapse until the star is created and shines like the sun