It's located in the nucleus
Answer:
The acceleration due to gravity is
times the value of g at the Earth’s surface.
(D) is correct option.
Explanation:
Given that,
Radius = 4000 miles
We need to calculate the gravitational force at surface
Gravitational force on the mass m on the surface of the earth
At r = R

....(I)
We need to calculate the gravitational force at height
Gravitational force on a mass m from the center of the earth,
At r = R + R = 2 R

....(II)
Dividing equation (II) by equation (I)


Hence, The acceleration due to gravity is
times the value of g at the Earth’s surface.
Answer:
The moment of inertia is 
Explanation:
The moment of inertia is equal:

If r is 
and 


Answer:
t = 2.58*10^-6 s
Explanation:
For a nonconducting sphere you have that the value of the electric field, depends of the region:

k: Coulomb's constant = 8.98*10^9 Nm^2/C^2
R: radius of the sphere = 10.0/2 = 5.0cm=0.005m
In this case you can assume that the proton is in the region for r > R. Furthermore you use the secon Newton law in order to find the acceleration of the proton produced by the force:

Due to the proton is just outside the surface you can use r=R and calculate the acceleration. Also, you take into account the charge density of the sphere in order to compute the total charge:

with this values of a you can use the following formula:

hence, the time that the proton takes to reach a speed of 2550km is 2.58*10^-6 s