1a. The thermal energy store of the ball and the surroundings increases. The gravitational energy store of the ball decreases. 1b i) ∆GPE = weight x ∆h ∆GPE = 1.4N x ( 2.5m - 1.7m ) ∆GPE = 1.4N x ( 0.8 m) ∆GPE = 1.12 J 1bii) Air resistance and in elastic deformation of the ball causes a rise in the thermal store of the ball and its surroundings.

2a i) ∆GPE = weight x ∆h ∆GPE = 450 N x ( 0.2m ) ∆GPE = 90 J 2bi) ∆GPE = 90 J x 50 times 2bii) ∆GPE = 4,50 0 J

3a i) ∆GPE = mass x gravitational field strength x ∆h ∆GPE = 25 kg x 9.8 N/kg x 1.8 m ∆GPE = 441 J 3b ii) ∆ GPE = mass x gravitational field strength x ( 1.8m – 0.3m ) ∆ GPE = 25 kg x 9.8 N/kg x ( 1.8 – 0.3 ) m ∆ GPE = 25 kg x 9.8 N/kg x ( 1.8 – 0.3 ) m ∆ GPE = 367.5 J or 370 J ( to 2 sig figs )

4. The thermal energy store of the surroundings increases.