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Question 1.5: When leaving a town, a car accelerates from 30 mph to 60 mph...

When leaving a town, a car accelerates from 30 mph to 60 mph in 5 s. Assuming the acceleration is constant, find the distance travelled in this time.

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Let the distance travelled be s miles. You want s and are given u = 30, v = 60 and t = 5  ÷ 3600 so you need an equation involving u, v, t and s.

s = \frac{(u  +  v)}{2} × t

s = \frac{(30  +  60)}{2} × \frac{5}{3600}

= \frac{1}{16}

The distance travelled is \frac{1}{16} mile or 110 yards. (One mile is 1760 yards.)

fig 1.30

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