First, write down the information given and the change units if necessary (we must have similar units to operate on).
Initial speed, u = 36 km/h = 10 m/s
Final speed, v = 72 km/h = 20 m/s
Distance, s = 100 m
We know that
[tex] {v}^{2} - {u}^{2} = 2as \\ {20}^{2} - {10}^{2} = 2 \times a \times 100 \\ 400 - 100 = 200 \times a \\ a = \frac{300}{200 } = \frac{3}{2} \: m {s}^{ - 2} [/tex]
Now, we substitute v, u, and a in the formula
[tex]v = u + at \\ 20 = 10 + \frac{3}{2} t \\ \frac{3}{2} t = 10 \\ 3t = 20 \\ t = \frac{20}{3} = 6.67 \: seconds[/tex]
Please mark Brainliest if this helps!
