1- A 5.76 kg object falls freely (ignore air resistance), after being dropped from rest. Determine the initial kinetic energy (in J), the final kinetic energy (in J), and the change in kinetic energy (in J) for the following.

(a)

the first meter of the fall

initial kinetic energy= J

final kinetic energy= J

change in kinetic energy= J

b)

the second meter of the fall

initial kinetic energy= J

final kinetic energy= J

change in kinetic energy= J

2- (a)

Find the useful power output (in W) of an elevator motor that lifts a 2700 kg load a height of 40.0 m in 12.0 s, if it also increases the speed from rest to 4.00 m/s. Note that the total mass of the counterbalanced system is 10,000 kgso that only 2700 kg is raised in height, but the full 10,000 kg is accelerated. (Enter a number.) W

(b)

What does it cost (in cents), if electricity is $0.0900 per kW h? (Enter a number.) cents