Question

A car starts off to race with initial velocity 50 m/s and then retards with 10 m/s2
. Calculate
the time taken by it to cover a distance of 125 m.

Answer 1

Answer:

Time (t) = 5 seconds

Explanation:

Initial velocity (u) = 50 m/s

Retardation = 10m/s²

Distance (S) = 125m

Applying, S = ut - (1/2) at² , we have

$125 = (50 \times t) - \: \frac{1}{2} \times 10 \times {t}^{2} \:$

125 = 50t - 5t²

5t² - 50t + 125 = 0

5(t² - 10t + 25) = 0

=> t² - 5t - 5t + 25 = 0

t(t - 5) -5(t - 5) = 0

(t - 5)² = 0

t = 5