Question

Given that v = vo + gt, when a rock is pushed off a cliff and free falls to the ground, after 3.8 seconds, its velocity after 9.8 seconds is 197.0 m/s. What is the initial velocity (vo) of the rock?

A. 10 m/s
B. 20 m/s
C. 30 m/s
D. 40 m/s

Answer 1

The initial velocity of the rock is 234.24 m/s.

None of the given options is correct

Step-by-step explanation:

To solve for the initial velocity (vo) of the rock, we can use the given equation v = vo + gt, where v is the final velocity, g is the acceleration due to gravity (approximately -9.8 m/s²), and t is the time.

Given that after 3.8 seconds, the velocity is 197.0 m/s, we can plug in these values into the equation:

197.0 m/s = vo + (-9.8 m/s²)(3.8 s)

Simplifying the equation, we get:

197.0 m/s = vo - 37.24 m/s²

Now, isolate the vo term:

vo = 197.0 m/s + 37.24 m/s² = 234.24 m/s.

Therefore, the initial velocity (vo) of the rock is 234.24 m/s.

None of the given options is correct