Answer:

Explanation:
It is given that,
Depth of Death valley is 85 m below sea level, 
The summit of nearby Mt. Whitney has an elevation of 4420 m, 
Mass of the hiker, m = 65 kg
We need to find the change in potential energy. It is given by :



or

So, the change in potential energy of the hiker is
. Hence, this is the required solution.
The height attained by the ball is 11.86m
a ball is shot from the ground straight up into the air its initial and final velocity is
initial velocity, u = 50 ft/s = 50×0.305 = 15.25m/s
final velocity ,v = 0 m/s
gravity =-9.8 m/s²
( negative sign shows acceleration in opposite direction)
height =?
using the newton motion of equation
v² = u² + 2as
where
a= acceleration due to gravity(g)
s = height
v² = u² + 2gs
(0)² = (15.25)² + 2×(-9.8)×s
0 = (15.25)² - 19.6 × s
s= - (15.25)²/ 19.6
s = 11.86m
after ignoring the air resistance the maximum height of the ball is 11.86m
To learn more about motion under gravity -
brainly.com/question/27962354
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