1. Light bulbs produce useful energy in the form of light and waste energy in the form of heat. What kind of light bulb would you use to incubate eggs?

A) high-efficiency light bulbs because they produce more heat
B) High efficiency light bulbs because they produce more light
C) low efficiency light bulbs because they produce more heat
D) low efficiency light bulbs because they produce more light

2. A machine has an efficiency of 15%. If the energy input is 300 joules, how much useful energy is generated?

A) 285 joules
B) 45 joules
C) 255 joules
D) 20 joules

3. A process generates 250 watts of useful energy and 609 watts of waste energy. What is the efficiency of the process?

A) 29%
B) 71%
C) 2.4%
D) 42%

4. A wheel and axle on a bicycle are designed with an axle radius of 0.5 feet and a wheel radius of 2 feet. If a force of 200 pounds is applied to the axle, what is the maximum output force of the bike wheel?

A) 1200 lb
B) 200 lb
C) 50 lb
D) 800 lb

5) a crowbar is being used with an actual mechanical advantage of 8. If the input force is 400 Newton’s on the 0.3-meter-long end of the crowbar, what is the output force on the short end?

A) 120 N
B) 960 N
C) 50 N
D) 3200 N

pls help me