A stone has initial potential, kinetic and internal energy 7 J, 10 J and 2x J respectively, if the final kinetic energy, potential energy and internal energy are 5 J, 21 J and x respectively, what is the final internal energy?

A stone has initial potential, kinetic and internal energy 7 J, 10 J a

1.	A stone has initial potential, kinetic and internal energy 7 J, 10 J and 2x J respectively, if the final kinetic energy, potential energy and internal energy are 5 J, 21 J and x respectively, what is the final internal energy?
A.	t2 J
B.	t4 J
C.	t5 J
D.	t9 J
Answer» E.