A ball is thrown upward with a speed of 30 m/s.About how long after it was thrown will the ball reach the ground?
A)1.5 s
B)3.1 s
C)6.1 s
D)12.2 s

Question

Quizplus · Accepted Answer

We can use the equation h = vit + (1/2)at^2, where h is the height, vi is the initial velocity, a is the acceleration due to gravity (-9.8 m/s^2), and t is the time.

When the ball reaches the ground, its height is 0. Therefore, we can write:

0 = 30t - (1/2)(9.8)t^2

Simplifying:

4.9t^2 - 30t = 0

We can factor out t:

t(4.9t - 30) = 0

The solutions are t = 0 (which doesn't make sense in this context) and t = 6.1 s.

Therefore, the ball will reach the ground about 6.1 seconds after it was thrown.

A Ball Is Thrown Upward with a Speed of 30