Question 4
An object has a mass of 600 g. What is its momentum at a moment when its velocity is 5 m s−1?
The right answer is the one marked above.
3 kg m s−1. The mass is given in grams, so it must be converted to kilograms first:
600 g = 600 ÷ 1000 = 0.6 kg
momentum = 0.6 kg × 5 m s−1 = 3 kg m s−1
3000 comes from substituting 600 directly — the commonest slip here. For momentum the mass must always be in kg.