4.10

1.       Copy and complete these sentences.

a) The work done (measured in JOULES) is equal to the WEIGHT (in Newton’s) multiplied by the DISTANCE moved (in metres).

b) 1 Joule is the work done when a force of one NEWTON moves through a distance of 1 METRE (in the direction of force)

c) Work done =  ENERGY transferred.

2.      A man lifts a parcel weighing 5 Newton’s from the ground to a shelf 2 metres high. How much work does he do on the parcel?

Wd = F * d

Wd = 5 * 2

Wd =  10J

3.      A girl weighing 500N climbs 40m vertically when walking up the stairs in an office block. How much work does she do against gravity? What are the energy transfers here?

Wd= F* d

Wd= 500*4

Wd= 2000J

4.10

10 June 2011

11:51

·         4.10 understand that work done is equal to energy transferred

PFY p.112

Collins p. 91