Physics (AS & A Level) · May / June 2016 · Paper 41 · Question 1

(gravitational) potential at infinity defined as/is zero (gravitational) force attractive so work got out/done as object moves from infinity (so potential is negative) [2]

∆E = m∆φ = 180 × (14 – 10) × 108 = 7.2 × 1010 J increase [3]

energy required = 180 × (10 – 4.4) × 108 or energy per unit mass = (10 – 4.4) × 108 ½ × 180 × v2 = 180 × (10 – 4.4) × 108 or ½ × v2 = (10 – 4.4) × 108 v = 3.3 × 104 m s–1 [3]