225k views
4 votes
Positivephysics

Dashb
A student drops a ball from a height of 30.0m. Determine all unknowns and answer
the following questions. Neglect drag.
How long did the ball remain in the air?
unit
What was the ball's speed just before striking the ground?
unit

1 Answer

6 votes

Final answer:

The ball remained in the air for approximately 2.47 seconds and had a speed of approximately 24.2 m/s just before striking the ground.


Step-by-step explanation:

To determine the time the ball remained in the air, we can use the equation:

h = 0.5 * g * t^2

Where h is the height, g is the acceleration due to gravity (which is approximately 9.8 m/s^2), and t is the time the ball remained in the air.

Using the given height, we can rearrange the equation to solve for t:

t = √(2 * h / g)

Plugging in the values, we have t = √(2 * 30.0m / 9.8 m/s^2) = √6.12 s ≈ 2.47 s.

To find the ball's speed just before striking the ground, we can use another equation:

v^2 = u^2 + 2 * g * h

Where v is the final velocity, u is the initial velocity (which in this case is 0 m/s since the ball was dropped), g is the acceleration due to gravity, and h is the height. Rearranging the equation, we have:

v = √(u^2 + 2 * g * h)

Plugging in the values, we have v = √(0 + 2 * 9.8 m/s^2 * 30.0m) = √588 m^2/s^2 ≈ 24.2 m/s.


Learn more about the time the ball remained in the air and the ball's speed before striking the ground

User Lsiu
by
7.3k points