Question

A golf ball is hit from the ground with an initial speed of 192 feet per second. Assume the starting height of the ball is 0 feet. How long will it take the golf ball to hit the ground? (2 points)

Group of answer choices

39 secs

19 secs

12 secs

6 secs

Answer 1

option C.

Explanation:

Given,

Initial speed of the ball, v = 192 ft/s

Distance travel, h(t) = 0 ft

Acceleration due to gravity, g = 32 ft/s²

Using equation of motion

`s = ut + (1)/(2)gt^2`

`0 = 192t - (1)/(2)* 32t^2`

`16t(t-12)=0`

t = 12 s.

Hence, the time for which ball was in the air is equal to 12 s.

Hence, the correct answer is option C.

Answer 2

39secs

Explanation:

Using the equation of motion

S = ut + 1/2gt²

S is the distance or height covered by the golf ball.

t is the time taken by the ball to hit the ground

U us the initial speed of the ball

g is the acceleration due to gravity.

g will be negative since the body acts against gravity

Given S = 0feet

u = 192ft/s

g = -9.81m/s²

t = ?

Substituting the parameters into the formula:

0 = 192t-1/2(9.81)t²

-192t = -4.91t²

4.91t = 192

t = 192/4.91

t = 39.1secs

The time taken by the golf ball to hit the ground is approximately 39secs