Work and Power

Question 1

what is work done

Answer 1

Work done is the amount of energy used up when you move an object by force
Work done, W (Joules/J) = Force, F (N) x distance, d (m)

Question 2

what is the unit of work done

Answer 2

Work done is a measure of energy, so its unit is Joules

Question 3

what analogy helps understand work done

Answer 3

Think of carrying a 20kg bag of rice from the shop all the way home (500m) or carrying it from your driveway into the house (5m). Which would be easier? Driveway, as it is a much shorter distance, so it takes less energy. In physics, instead of takes/uses less energy, we say less work is done.

Question 4

what is the formula for GPE

Answer 4

GPE = mass in kg (m) x gravitational field strength in N/kg (g) x height in meters (h)

Question 5

what is GPE

Answer 5

GPE is the energy store dependent on the height of an object. If its height increases, the energy in its GPE store will increase. If its height decreases, the energy in its GPE store will decrease.

Question 6

what is Kinetic energy

Answer 6

Kinetic energy is the energy when an object is moving. So the faster it moves, the more energy in its kinetic store, and the slower, the less energy.

Question 7

what is the equation linking power with work done

Answer 7

P = work done / t, since in electricity P= E/t energy transfered is = to work donee