3. Work and Energy
Power And Efficiency — Quiz
Test your understanding of power and efficiency with 5 practice questions.
Practice Questions
Question 1
A machine lifts a 60 kg mass to a height of 15 meters in 5 seconds. What is the average power output of the machine? (Assume $g = 9.8 \text{ m/s}^2$)
Question 2
If a machine has an efficiency of 85% and consumes 1200 J of energy, how much useful work does it perform?
Question 3
A motor operates at an efficiency of 90%. If it outputs 540 W of useful power, what is its input power?
Question 4
A force of 30 N is applied to move an object 6 m in 3 seconds. What is the average power exerted?
Question 5
If the instantaneous power delivered to an object is given by $P(t) = 4t + 2$, what is the power at $t = 5 \text{ s}$?