How much work is required to stop an electron
(m = 9.11 x 10-31 kg)
110 x 10° m/s?
which is moving with a speed of 110 x 10° m/s?

Askydiver weighing 140 lb (including equipment) falls vertically downward from an altitude of 19,000 ft and opens the parachute after 18 s of free fall. assume that the force of air resistance, which is directed opposite to the velocity, is of magnitude 0.55|v| when the parachute is closed and is of magnitude 14|v| when the parachute is open, where the velocity v is measured in ft/s. assume that acceleration due to gravity has magnitude 32 ft/s/s; remember that weight is the product of mass and gravitational acceleration. (a) find the speed of the skydiver when the parachute opens. (b) find the distance fallen before the parachute opens. (c) what is the limiting velocity vl after the parachute opens? (d) determine how long the sky diver is in the air after the parachute opens. (e) plot the graph of velocity versus time from the beginning of the fall until the skydiver reaches the ground.

Which best describes the difference between internal and thermal energy?

Which of the following conditions lead you to see an absorption line spectrum from a cloud of gas in interstellar space? the cloud is extremely hot. the cloud is visible primarily because it reflects light from nearby stars. the cloud is cool and lies between you and a hot star. the cloud is cool and very dense, so that you cannot see any objects that lie behind it.