Answer:
h = 2.49 [m]
Explanation:
In order to solve this problem we must use the definition of potential energy, which tells us that energy is equal to the product of mass by gravity by height.
The potential energy can be calculated by means of this equation:
Ep = m*g*h
where:
Ep = potential energy = 980 [J]
m = mass = 40 [kg]
g = gravity acceleration = 9.81 [m/s^2]
h = elevation [m]
Now replacing:
980 = 40*9.81*h
h = 2.49 [m]
B) The amount of work done
So we want to explain the effects of time dilation. In theory of relativity time dilation is the difference of elapsed time between two events when measured by two observers who are moving relatively to each other. A clock of an observer that is standing still in an inertial frame of reference is going to measure a different time of an event than the clock of an observer that is moving with some velocity with respect to the inertial reference frame that is not moving. In a nutshell, the moving clock is ticking slower than the clock that is standing still.
