Zorch, an archenemy of superman, decides to slow earth’s rotation to once per 28.0 h by exerting an opposing force at and parallel to the equator. superman is not immediately concerned, because he knows zorch can only exert a force of 4.00×107n (a little greater than a saturn v rocket’s thrust). how long must zorch push with this force to accomplish his goal?

Explanation:

Torque due to applied force along its surface is given as

here we know that

r = radius of earth =

Now we have

now we know that

initial angular speed of Earth is

final angular speed will be

so now we have

here we have moment of inertia of Earth is given as

now we have

its c i just checked it

one person pulls 90n one way and the other has 100n pulling the other way.

so the net force = 90 - 100 = -10n,

or the ans can be 10n if the picture shows -90n and 100n instead.