Which of the following statements is true?
1 nitrogen leaves the atmosphere through precipitation.
2 carbon dioxide is released into the atmosphere through plant leaves.
3 carbon dioxide is inhaled by animals.
4 most ozone is found in the lower atmosphere.

An object moves from the position +34m to the position -15m in 15 seconds. what is it's total displacement? what is it's average velocity?

Boxing gloves are padded to lessen the force of a blow. (a) calculate the force exerted by a boxing glove on an opponent’s face, if the glove and face compress 7.50 cm during a blow in which the 7.00-kg arm and glove are brought to rest from an initial speed of 10.0 m/s. (b) calculate the force exerted by an identical blow in the gory old days when no gloves were used and the knuckles and face would compress only 2.00 cm. (c) discuss the magnitude of the force with glove on. does it seem high enough to cause damage even though it is lower than the force with no glove?

What is the average speed of a car that travels 40 mph for 1 hour and 60 mph in another hour?