Question

A student is holding a stone at a certain height. The stone has 50 joules of potential energy and 0 joules of kinetic energy. The stone is released from that height. How much energy does the stone have
right before it hits the ground?
Select one:
a) The stone will have no energy
b) The stone will have about 25 joules each of kinetic and potential energy
c) The stone will have about 50 joules of potential energy and ovogres van kinetic
energy
d) The stone will have about 50 joules of kinetic energy and ovoules of potencia
energy​

Answer 1

Answer:

d) The stone will have about 50 joules of kinetic energy and 0 joules of potential energy​ .

Explanation:

Given :

Initial Potential energy , $P_i=50\ J$ .

Initial Kinetic energy , $K_i=0\ J$ . ( because ball is in rest )

Now , we know , kinetic energy is maximum when an object reaches ground .

Also , potential energy is zero when an object is in ground .

We know , by conservation of energy :

Initial total energy = Final total energy

$P_i+K_i=P_f+K_f\\\\50+0=0+K_f\\\\K_f=50 \ J$

Therefore , option d) is correct .