Answer:False
Explanation:
Work is being done on a body when it causes displacement of body on the application of force

When we pull the door by a force it causes zero displacements of the door. So we can say that work done on it is zero.
Thus the above-given statement is false
Answer: The period of the pendulum will increase. Because of less gravity
Explanation:
Since the force of gravity is less on the Moon, the pendulum would swing slower at the same length and angle and its frequency would be less. Hence more time period will be experienced by the pendulum. On the moon, the acceleration due to gravity g is less when compared to that of the earth.
Answer:
125.83672 seconds
Explanation:
P = Power of the horse = 1 hp = 746 W (as it is not given we have assumed the horse has the power of 1 hp)
m = Mass of professor = 103 kg
g = Acceleration due to gravity = 9.8 m/s²
h = Height of professor = 93 m
Work done would be equal to the potential energy

Power is given by

The time taken by the horse to pull the professor is 125.83672 seconds
The Luminosity of a star is proportional to its Effective Temperature to the 4th power and its Radius squared.