Question

5. Acar starts from rest and moves along the x-axis with constant acceleration
5 m s-2 for 8 seconds. If it then continues with constant velocity, what
distance will the car cover in 12 seconds since it started from the rest?​

Answer 1

Given:

a = 5m/s²

t = 8 sec

u = 0 m/s

To Find:

$s_{1}$ = ?

Total distance = ?

we know that

$\: \: \: \: \sf s_{1} = ut + \frac{1}{2} a {t}^{2} \\ \sf = 0 + \frac{1}{2} \times 5 \times {8}^{2} \\\sf s_{1} = 160 \: m$

• The velocity attained in 8 seconds is given by $\sf \: v = u + at \\ \sf \:0 + 5 \times 8 = 40ms ^{ - 1}$

• The distance traveled in the next 4 seconds is $\sf \: s_{2} = 40 \times 4 = 160m$

So, the total distance traveled by the car is $\sf s_{1} + s_{2} = 160 + 160 = 320 \: m$