Question

Julia jumps straight upward on mars, where the acceleration due to gravity is 3.7 m/s² downward. After 3 seconds, Julia is falling downward with a velocity of 3.1 m/s. Assuming air resistance is negligible, what was the initial vertical velocity of Julia's jump? Answer using a coordinate system where upward is positive.

Answer 1

The initial vertical velocity of Julia's jump on Mars was -8 m/s.

Step-by-step explanation:

To determine the initial vertical velocity of Julia's jump on Mars, we can use the following kinematic equation:

v = u + at

where:
v = final velocity = 3.1 m/s (downward)
u = initial velocity
a = acceleration due to gravity = 3.7 m/s² (downward)
t = time = 3 seconds

Plugging in the given values, we can solve for u:

3.1 = u + (3.7)(3)

Simplifying the equation gives:

u = 3.1 - (3.7)(3)

u = 3.1 - 11.1

u = -8

The initial vertical velocity of Julia's jump was -8 m/s, meaning she jumped downward with an initial velocity of 8 m/s.