Question 5
A force of 30 N applied to an object produces an acceleration of 1.5 m s−2. What is the object's mass?
The right answer is the one marked above.
20 kg. The unknown here is the mass:
30 = m × 1.5
m = 30 ÷ 1.5 = 20 kg
Check it: 20 kg × 1.5 m s−2 = 30 N. ✓
45 kg comes from multiplying (30 × 1.5). When dividing by a decimal, think about whether the answer should come out bigger or smaller.