Question

A ball is thrown straight upwards with an initial velocity of +20 m/s. The entire time it is in the air it has a constant acceleration of -9.80 m/s/s and then it returns to the initial height with a final velocity of -20 m/s. How long is it in the air for?

Answer 1

The ball is in the air for approximately 4.08 seconds.

Step-by-step explanation:

To find the time for the ball to be in the air, we can use the equation:

t = (v - vo) / a

where t is the time, v is the final velocity, vo is the initial velocity and a is the acceleration.

Substituting the given values:

1. v = -20 m/s
2. vo = 20 m/s
3. a = -9.80 m/s^2

we have:

t = (-20 - 20) / -9.80

t = 40 / 9.80

t = 4.08 seconds

Therefore, the ball is in the air for approximately 4.08 seconds.