A Stone Is Thrown Vertically Upward With A Speed Of 30 M/S., A) What Is The Maximum Height Reached By The Stone?, B) How Many Seconds Will It Take For

A stone is thrown vertically upward with a speed of 30 m/s.

a) What is the maximum height reached by the stone?

b) How many seconds will it take for the stone to reach the ground?

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Problem:

A stone is thrown vertically upward with a speed of 30 m/s.

a) What is the maximum height reached by the stone?

                            Answer: height = 45.915 m

Given data:

Vi (initial velocity) = 30 m/s

Vf (final velocity) = 0 m/s (maximum height the stone stop)

a (acceleration) = -9.8 m/s²

d (distance) = ? unknown

Solution:

We need to solve for time first:

t = (Vf-Vi) / a

 = 0 - 30 m/s / - 9.8 m/s²

  = - 30 m/s / - 9.8 m/s²

t  = 3.061 seconds

Solving for distance:

d = (Vf+Vi)/2 × t

  = (0 m/s + 30 m/s)/2 × 3.061 s

  = 15 m/s × 3.061 s

d = 45.915 m

b) How many seconds will it take for the stone to reach the ground?

                         Answer:  6.122 seconds

The time it take the ball to reach the maximum height is 3.061 seconds and it would also take 3.061 seconds for the ball to return to its initial elevation. Which means it would take 6.122 seconds for the ball to reach the ground.

Given :

time going up = 3.061 s

time going down = 3.061 s

total time = unknown?

total time = 3.061 s + 3.061 s

                 =  6.122 seconds