Answer:
51.94 ft/s²
257.63 ft/s
Explanation:
t = Time taken = 4 s
u = Initial velocity = 34 mi/h
v = Final velocity
s = Displacement = 615 ft
a = Acceleration
Converting velocity to ft/s
Equation of motion
Acceleration is 51.94 ft/s²
Final velocity at this time is 257.63 ft/s
Given,
Distance from the surface to the center of the earth, d=4000 miles
Distance from the center to you at a height of 8000 miles, a= 8000+4000=12000 miles
The gravitational force acting on a person at the surface is equal to his weight.
From Newton's Universal Law of Gravitation, the gravitational force is
Where G is the gravitational constant, M is the mass of the earth, m is the mass of the object/person, r is the distance between the center of the earth and the object/person
At the surface, this force is equal to the weight of the person, W=mg
i.e.
On substituting the of d,
At a height of 8000 miles from the surface, the gravitational force is equal to,
On dividing the above two equations,
Therefore,
Therefore at a height of 8000 miles above the surface of the earth, the force of gravity becomes 1/9 time your weight.