Question

Work & Power Problems

⦁ What are the correct units for work? What is the formula for work?

⦁ The unit for Force is .
⦁ For something to be considered “work”, distance must be in the direction of .
⦁ Give one example of work being done in everyday life.

⦁ What are the correct units for POWER? What is the formula for power?

⦁ In the power lab, the students with less mass produced [MORE OR LESS] power.

⦁ In the power lab, which students had to do the most work to get up the stairs?

⦁ Calculate the work done by a 47 N force pushing a pencil 0.26 m.

⦁ Harold places a force of 30 N. on an object and it moves a distance of 14 m. How much work was done on the object?

⦁ You must exert a force of 4.5 N on a book to slide it across a table. If you do 2.7 J of work in the process, how far have you moved the book?

⦁ A child pulls a sled up a snow-covered hill. The child does 405 J of work on the sled. If the child walks 15 m up the hill, how large of a force must the child exert?


⦁ How much work is done on a small car if a 3150 N force is exerted to move it 75.5 m to the side of the road?


⦁ A crate is being lifted into a truck. If it is moved with a 2470 N force and 3650 J of work is done, then how far is the crate being lifted?


⦁ If 16,700 J of work is done to shoot the human cannonball down a 3.05 m barrel, then how much force is applied to the person to fire them out the cannon?


⦁ An elephant pushes with 2000 N on a load of trees. It then pushes these trees for 150 m. How much work did the elephant do?

⦁ How much power does it take to lift 30.0 kg 10.0 m high in 5.00 s?

⦁ You move a 25 N object 5.0 meters. How much work did you do?

⦁ A 190,000 W engine can accelerate from rest to a top speed in 9 s. How much work did the engine do?


⦁ If a runner exerts 350 J of work to make 125 W of power, then how long did it take the runner to do the work?

Electricity Problems
⦁ Do insulators or conductors allow electrons to move easily through?

⦁ Give one example of a conductor and one example of an insulator.
⦁ Lightning is an example of what kind of electricity?

⦁ What was happening when John Travolta’s foot was rubbed on the carpet?

⦁ Potential difference is another term used for .

⦁ Define current.

⦁ is measured in Ohms.

⦁ is measured in Amperes (A).

⦁ The amount of resistance depends on what? (list 2 things)


⦁ What is a closed path through which electrons can flow?

⦁ State the Ohm’s Law formula.

⦁ As current decreases, voltage .

⦁ As resistance increases, voltage .

⦁ Calculate the current in the circuit below. 13. Calculate the resistance in the circuit below.
(The symbol E in the image below is equivalent to Voltage, V.)


14. Calculate the voltage in the circuit below.

15. What are 2 differences between a parallel circuit and a series circuit?



16. What is the formula for electrical power? What are the correct units?

Answer 1

1. Unit for work is measured in Joules.

Formula for work is power * time taken

2 The unit for force is Newton

A work done in lifting a jar of water

3. The unit for measuring power is Joules.

The formula for measuring power is work done/time taken