ANSWER FOR QUESTION 3: The answer would be B.) because work or energy, is equal to the work done by a force, like the ball.
ANSWER FOR QUESTION 4: The answer would be D.) because when a ball roles down a hill the work to push that ball can transfer energy between the ball or other objects and cause the change in the total amount of energy used.
ANSWER FOR QUESTION 5: The answer is mechanical, because both physical and constant, kenitic and potential.
To dissolve, solvent particles must come in contact with solvent particles. Particles of hot water are moving much more rapidly than particles of cold water. Hence, in hot water more water particles will come in contact with hot chocolate powder than in cold water, resulting in faster dissolving.
The trapping of the sun's warmth in a planet's lower atmosphere due to the greater transparency of the atmosphere to visible radiation from the sun than to infrared radiation emitted from the planet's surface.
When organisms produce more offspring than survive, the area can become overcrowded, and they will compete for nutrients and other resources and necessities.