Physics - Kinematics Question with Solution | TestHub

Using equation, $a=\frac{v-u}{t}$ and $$S=ut+\frac{1}{2}a{t}^2$$ Distance travelled by car in $15\sec$ $=\frac{1}{2}\frac{(45)}{15}(15{)}^2$ $=\frac{675}{2}\mathrm{m}$ Distance traveled by scooter in 15 seconds $=30\times 15=450(\because$ distance $=$ speed $\times$ time $)$ Difference between distance travelled by car and scooter in $15\sec ,450-337.5=112.5\mathrm{m}$ Let car catches scooter in time t; $\frac{675}{2}+45(t-15)=30t$ $337.5+45\mathrm{t}-675=30\mathrm{t}$ $\Rightarrow 15\mathrm{t}=337.5$ $\Rightarrow \mathrm{t}=22.5\sec$