Question

Julia jumps straight upward on Mars, where the acceleration due to gravity is 3.7\,\dfrac{\text{m}}{\text{s}^2}3.7 s 2 m ​ downward. After 3\,\text{s}3s, Julia is falling downward with a velocity of 3.1\,\dfrac{\text{m}}{\text{s}}3.1 s m ​ . Assuming air resistance is negligible, what was the initial vertical velocity of Julia's jump?

Answer 1

Answer: The initial vertical velocity of Julia's jump is 8 m/s

Explanation:

Given that,

Acceleration due to gravity upward $a = -3.7 m/s^{2}$

Time t = 3 s

Final velocity v = -3.1 m/s

Negative sign indicates downward direction

Using equation of motion

$v = u+ at$

$-3.1\ m/s = u - 3.7 m/s^{2} \times 3 s$

$u = 8\ m/s$

Hence, the initial vertical velocity of Julia's jump is 8 m/s.