The end of which era left many plants, insects, and salamander-like animals on the earth?
a. the precambrian time
c. the paleozoic era
b. the mesozoic era
d. the cenozoic era

Agalvanometer has an internal resistance of 100 ω and deflects full-scale at 2.00 ma. what size resistor should be added to the galvanometer to convert it to a milliammeter capable of reading up to 4.00 ma, and how should this resistor be connected to the galvanometer?

Amass weighing 24 pounds, attached to the end of a spring, stretches it 4 inches. initially, the mass is released from rest from a point 8 inches below the equilibrium position. find the equation of motion. (use g = 32 ft/s2 for the acceleration due to gravity.)

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.