When potential energy decreases, kinetic energy

According to the law of conservation of mass, in a chemical reaction the total starting mass of all the reactants equal the total final mass of all the products. true or false?

How does the kinetic energy of a charge change as the charge moves under the effect of an electric field from higher potential to lower potential? a. the kinetic energy increases. b.the kinetic energy decreases. c.the kinetic energy remains the same. d.the kinetic energy is always zero.

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?