Answer: Gravitational force between the two masses does not depend on the medium separating two masses.
Answer:

Explanation:
First, let's find the voltage through the resistor using ohm's law:

AC power as function of time can be calculated as:
(1)
Where:

Because of the problem doesn't give us additional information, let's assume:

Evaluating the equation (1) in t=3600 (Because 1h equal to 3600s):

The acceleration of an object depends directly upon the net force acting upon the object, and inversely upon the mass of the object. As the force acting upon an object is increased, the acceleration of the object is increased. As the mass of an object is increased, the acceleration of the object is decreased.
Answer:
Explanation:
Gravity pulls everything down at the same rate of 9.8 m/s/s. If you're looking for the normal force, which is the same as the weight of the object, we'll find that, just in case.
w = mg which says that the normal force/weight of an object is equal to its mass times the pull of gravity:
w = 4.0(9.8) so
w = 39N
Answer:
Half
Explanation:
You only have to exert a force equal to half the weight of the load to lift it.