1. What is the efficiency of a subject on a treadmill who puts out work at the rate of 105 W while consuming oxygen at the rate of 2.00 L/min?

1. What is the efficiency of a subject on a treadmill who puts out work at the rate of 105 W while consuming oxygen at the rate of 2.00 L/min?(Hint:If the oxygen consumption is 2.00 L/min,then the power input is 700 W.) _______________

2. A person in good physical condition can put out 100 W of useful power for several hours at a stretch, perhaps by pedaling a mechanism that drives an electric generator. Neglecting any problems of generator efficiency and practical considerations such as resting time, answer the following.

a) How many people would it take to run a 3.00 kW electric clothes dryer? _______ peopleb) How many people would it take to replace a large electric power plant that generates 700 MW?_________people

3. A large household air conditioner may consume 10.0 kW of power. What is the cost of operating this air conditioner 4.50 h per day for 40.0 d if the cost of electricity is \$0.130 per kW·