Important
1. A gas trapped in a cylinder does 540 J of work by expansion. At the end of the
process, the internal energy has decreased by 860 J.
a. How much energy was transferred as the heat between the gas and its environment?

Name three different units of energy used to measure heat and describe what type of situations each is usually used.

=force × distance a. work b. velocity c. pressure d. momentum

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?