Theory question 107
DynamicsA bus travels with a velocity of 6 ms−1. It then accelerates uniformly and travels a distance of 70 m. If the final velocity is 20 ms−1, find, correct to one decimal place, the: (a) acceleration; (b) time to travel this distance.
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Model answer
(a) v² = u² + 2as: 400 = 36 + 140a, so a = 364/140 = 2.6 ms⁻².
(b) v = u + at: 20 = 6 + 2.6t, so t = 14/2.6 ≈ 5.4 s.
Explanation
Choose the equation of motion that contains the quantities you know.