a dynamics assignment on WileyPLUS contain 4 problems

I routinely trot up the stairs to get to my office on the sixth floor from my third floor classroom and encourage my colleagues to 1)))do so as well. There are 12 steps (6 in. per step) per flight and two flights per floor. Assume it takes my colleague 13 s to go up a single floor, and he weighs 174 lb. What is his power output in watts?
2)))A 2400 lb car can accelerate from 0 to 66 mph in t = 5.1 s. If the drivetrain efficiency is 81%, determine the constant power output from the engine that is needed to accomplish this acceleration.
3)))How fast can a 3200 lb car with a 220 hp engine accelerate from 0 to 45 mph? Neglect drivetrain losses and air/road drag.

4)))How cheap is electricity? Let's work an example. I will assume a cost of $0.18 per kWh. Assume that you've constructed an elevator with an overall efficiency of 82%. (a) What is the cost of using this elevator to raise itself (270 kg) and a single passenger (60 kg) up four stories (19 m)? (b) What is the average power needed if it takes 20 s to complete the trip?