The total mass of a wheelbarrow and its load is 90kg. A worker pushes the wheelbarrow and load up a plank of length 2.0m on to a platform, as shown in Fig. 2.1. The platform is at a height of 0.60 m above the ground. [Figure 2.1] The worker exerts a force of 290 N on the wheelbarrow in the direction in which the wheelbarrow moves.

1. (a)The gravitational field strength g is equal to 10N/kg.
2. (a)(i)Calculate the gravitational potential energy gained by the wheelbarrow and its load. energy =[2]
3. (a)(ii)The worker pushes the wheelbarrow 2.0m along the plank. Calculate the work done on the wheelbarrow by the worker. work done =[2]
4. (a)(iii)Suggest one reason why the answer to (a)(ii) is not equal to the answer to (a)(i).[1]
5. (b)The worker finds that walking up the plank pushing the wheelbarrow is even more inefficient than the answers in (a) suggest.
6. (b)(i)State what is meant by efficiency.[1]
7. (b)(ii)Suggest one reason why this method of lifting the load onto the platform is so inefficient.[1]

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