A laser penis pointed at a dark wall. A spot of light is seen at exactly where the pen is pointing. Which property of light does this show?
A Light travels in a straight line.
B Light can pass through some surfaces
C
. Light can be reflected,
OD Light travels faster than sound,

Two masses are connected by a rope that hangs over a pulley as shown below. the pulley is a uniform cylinder of radius 푅=0.381meters and mass 푀=3.1푘푔. initially 푚"is on the ground and 푚#rests 2.5 meters above the ground. if the system is released, use conservation of energy to determine the speed of 푚#just before it strikes the ground. assume the pulley bearing is frictionless.