Given:
The potential energy of the marble when it is held in the air, PE=0.2 J
The mass of the marble, m=20 g
The initial kinetic energy of the marble, KE=0 J
To find:
(a) The total energy of the marble.
(b) The total energy of the marble before it hits the ground.
Step-by-step explanation:
(a)
The total mechanical energy of an object is the sum of its potential and kinetic energy.
Thus the total energy of the marble when it is dropped is
(b)
The total energy of an object will always remains the same as stated by the law of conservation of energy.
Thus the total energy of the marble will be the same as it energy when it was dropped.
Therefore, the total energy of the marble right before it hits the ground is \
Final answer:
a) The total energy of the marble when it is dropped is 0.2 J
b) The total energy of the marble right before it hits the ground is 0.2 J