Which of the following is not a physical change?
a Condensation
b Photosynthesis
С
Galvanization (adding a protective zinc layer
to a metal)
d None of the above
Astone weighing 1.5 kilograms is resting on a rock at a height of 20 meters above the ground. the stone rolls down 10 meters and comes to rest on a patch of moss. the gravitational potential energy of the stone on the moss is joules.
What is the change in internal energy if 20 j of heat is released from a system and the system does 50 j of work on the surroundings? a. -70 j b. 30 j c. -30 j d. 70 j