Question

If measuring experimental results, what can you predict about the work output of a 1200 watt hair dryer? the work output of the hairdryer will be less than the work input the work output of the hairdryer will be equal to the work input the work output of the hairdryer will be greater than the work input the work output of the hairdryer cannot be predicted in the real world

Answer 1

Answer: first option, the work output of the hairdryer will be less than the work input.

Explanation:

1) The work output measured in watts is the power of hair dryer measured in joules per second.

2) The hair dryer converts electrical energy from the wall outlet to mechanical and thermal energy: hot wind.

3) Nevertheless, you can never expect a 100% efficiency of the machines: due to friction, some energy is converted into useless energy.

So, efiiviency = power output / power input< 1 ⇒

power output = work output / time

input power = work input / time

⇒ work output / work input < 1

⇒ work output < work input.

Which is the first option: the work output of the hairdryer will be less than the work input

Answer 2

The work output of a 1200 wwtt hair dryer will be less than the work input. Work input is equal to Force times distance. To solve the mechanical efficiency it will be work output divided by work input times 100%. It is a simple machine so the work output is less than the work input which means the work. In addition, work output is overcomes friction causing it to lose its energy but there is still work done . Work input is equal to the work output plus the work done to overcome the friction.