Question

A truck travelling along a straight road at a constant speed of 72kph passes a car at time t=0 moving much slower. At instant the truck passes the car, the car starts accelerating at constant 1m/sq.sec and overtake the truck 0.6km further down the road, from where the car moves uniformly. Find the distance between them at t=50sec

Answer 1

$$\begin{gathered} u_c=0sppedoftruck \\ {u}_t=72km/h=20m/sfortruck \\ dis\tan cetarvelbytruckintimet=0.6km=600m \\ t=\frac{600}{20}=30s \\ aistheaccelerationofcar \\ s=ut+\frac{1}{2}a{t}^2 \\ 600=0+0.5\times a\times 900 \\ a=4/3m/s^2 \\ dis\tan cetarvelbycarin50seconds=\frac{1}{2}\times \frac{4}{3}\times 2500=5000/3m \\ dis\tan cetravelbytruckin50seconds=20*50=1000m \\ dis\tan cebetweenthem=\frac{5000}{3}-1000=2000/3m=666.66m \end{gathered}$$