Explanation:
The orbital radius of the Earth is 
The orbital radius of the Mercury is 
The orbital radius of the Pluto is 
We need to find the time required for light to travel from the Sun to each of the three planets.
(a) For Sun -Earth,
Kepler's third law :
M is mass of sun, 
So,
(b) For Sun -Mercury,
(c) For Sun-Pluto,
<span>At first when the car is at the datum
point where is no elevation, the kinetic energy increases while the potential
energy is zero. As it travel the path and goes upward the kinetic enrgy
decreases while the potential energy increases. When it goes down again the
kinetic enrgy increases again while the potential energy decreases </span>
Answer:
120,000J
Corrected question;
In one hour, coal supplies 500 000 J of energy. The wasted energy amounts to 380 000 J. How much useful energy is produced in one hour?
Explanation:
Given;
Total energy Et = 500,000 J
Wasted Energy Ew = 380,000J
The amount useful energy is the amount of energy that is available for supply.
This can be derived by subtracting the wasted energy from the total energy.
Useful energy = Total Energy - wasted energy
Eu = Et - Ew
Substituting the given values;
Eu = 500,000J - 380,000
Eu = 120,000 J
The amount of useful energy produced in one hour is 120,000 J
