Efficiency Practice

What equation should you use to determine the efficiency of a machine?

• $\%Eff=\frac{work_{out}}{work_{in}}\cdot100$

• $work_{out}=\frac{\%Eff\cdot work_{in}}{100}$

• $work_{in}=\frac{work_{out}\cdot100}{\%Eff}$

Tags

NGSS.HS-PS3-3

What equation should you use to determine the work input to a machine?

• $\%Eff=\frac{work_{out}}{work_{in}}\cdot100$

• $work_{out}=\frac{\%Eff\cdot work_{in}}{100}$

• $work_{in}=\frac{work_{out}\cdot100}{\%Eff}$

Tags

NGSS.HS-PS3-3

What equation should you use to determine the work output of a machine?

• $\%Eff=\frac{work_{out}}{work_{in}}\cdot100$

• $work_{out}=\frac{\%Eff\cdot work_{in}}{100}$

• $work_{in}=\frac{work_{out}\cdot100}{\%Eff}$

Tags

NGSS.MS-PS3-5

When you solve for work output, what unit should you use for your answer?

• joules (J)

• newtons (N)

• percent (%)

When you solve for efficiency, what unit should you use for your answer?

• joules (J)

• newtons (N)

• percent (%)

Tags

NGSS.HS-PS3-3

When you solve for work input, what unit should you use for your answer?

• joules (J)

• newtons (N)

• percent (%)

Which of the following would be the correct way to report a machine's efficiency?

• 60 J

• 60

• 60%

Which of the following would be the correct way to report a machine's work output?

• 60 J

• 60

• 60%

You input 100 J of work to a machine that gives 50 J of work output. What is the machine's efficiency?

• 150%

• 50%

• 2%

• 5000%

You solve a problem and find that you have machine with 150% efficiency. Can your answer be correct?

• No, the answer is wrong.

• Yes, the answer can be right.

• Not enough information to tell.