Which changes to observed time and length occur when objects approach the speed of light?
time moves slower and length increases.
time moves slower and length decreases.
time moves faster and length increases.
time moves faster and length decreases.

The boy of mass 30 kg is at r1= 2 meters from the fulcrum. of the girl is 45 kg, at what r2 must she sit so that they are balanced ?

Which articulations allow for greatest range of motion?

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?