Answer:
The change in gravitational potential energy of the climber-Earth system is 
Explanation:
From the question we are told that
The mass of the hiker is 
The time taken is 
The vertical elevation after time T is 
The change in gravitational potential is mathematically represented as

here g is the acceleration due to gravity with value
substituting values


Answer:
Explanation:
Given
Initial speed 
distance traveled before coming to rest 
using equation of motion

where v=final velocity
u=initial velocity
a=acceleration
s=displacement

for 
using same relation we get

divide 1 and 2 we get


So a distance if 213.32 ft is required to stop the vehicle with 80 mph speed