Work, energy and machines

Question 1 of 10

The efficiency of a machine is always less than 100% because of

Question 2 of 10

A lever with the fulcrum between the effort and the load, such as scissors, is

Question 3 of 10

A motor does 6000 J of work in 2 minutes. Its power is

Question 4 of 10

Find the kinetic energy of a 2 kg mass moving at 3 m/s.

Question 5 of 10

A machine gives out 300 J of useful work for every 400 J put in. What is its efficiency?

Question 6 of 10

A force of 50 N moves an object 4 m in the direction of the force. How much work is done?

Question 7 of 10

A pulley system with a velocity ratio of 4 lifts an 800 N load with an effort of 250 N. What is its efficiency?

Question 8 of 10

Efficiency of a machine is always less than 100% because of

Question 9 of 10

A 5 kg mass is raised through 4 m. What is its gain in potential energy?

Question 10 of 10

An inclined plane reduces the