The Earth has for the past 2 million years. A. gradually warmed slowly
B. frozen then quickly thawed
C. gradually cooled
D. stayed the same temperature
E. cycled between hot and cold

Abatter hits a 0.140-kg baseball that was approaching him at 30 m/s and, as a result, the ball leaves the bat at 40 m/s in the reverse of its original direction. the ball remains in contact with the bat for 2.0 ms. what is the magnitude of the average force exerted by the bat on the ball?

The ability to make things happen is also called a. heat b. force c. matter d. energy

To fully describe the photoelectric effect, scientists must consider which of the following to be quantized? o a. both light and matter o b. matter only o c. light only o d. neither light nor matter