When heat energy is transferred from direct contact between a warm and a cold object , it is known as heat transfer by conduction.
In conduction, the heat transfer takes place within an object or between two objects in contact until the temperature becomes uniform. this kind of heat transfer continues until the temperature at two ends between which the heat transfer take place , becomes equal. Heat transfer takes place from point at high temperature to point at lower temperature.
The element is iridium and it has 77 electrons
Answer : Height, h = 20.4 m
Explanation :
It is given that,
Mass of an object, m = 500 g = 0.5 kg
Gravitational potential energy, PE = 100 J
The Gravitational potential energy is the energy which is possessed due to the height and gravity of an object. It is given as :
PE = m g h
where,
h is the height of the cliff.

h = 20.40 m
So, the height of the cliff is 20.4 m.