The greenhouse effect becomes a problem

a. when there is an increase in solar radiation.
b. when there is an increase in the amount of greenhouse gases in the atmosphere.
c. when green plants produce too much oxygen, increasing the amount of oxygen in the atmosphere.

Polly is pushing a box across the floor with a force of 30 n. the force of gravity is –8 n, and the normal force is 8 n. which value could describe the force of friction if polly could not move the box?

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?

Another word for electromagnetic energy is a. heat b. force c. matter d. radiation