Question

A red car, travelling at 2 m/s, hit a blue car at rest. If the cars have equal masses of 2 kg, and the collision is elastic, what will be the speed of the red car immediately after the impact?

Answer 1

$\blue{\bold{\underline{\underline{Answer:}}}}$

$\green{\tt{\therefore{Velocity\:of\:red\:car\:after\:collision=1\:m/s}}}$

$\orange{\bold{\underline{\underline{Step-by-step\:explanation:}}}}$

$\green{\underline \bold{Given :}} \\ \tt : \implies Red \: car \: mass( m_{1}) = 2 \: kg \\ \\ \tt: \implies Velocity \: of \: car( v_{1}) =2 \: m/s \\ \\ \tt : \implies Blue \: car \: mass( m_{2}) = 2 \: kg \\ \\ \red{\underline \bold{To \: Find :}} \\ \tt: \implies Velocity\:of\:red\:car\:after\:collision( v_{c}) =?$

• According to given question :

$\tt \circ \: Velocity \: of \: m_{2} = 0 \: m/s\\ \\ \bold{As \: we \: know \: that} \\ \tt: \implies m_{1} v_{1} + m_{ 2 } v_{2} = ( m_{1} + m_{2}) v_{c} \\ \\ \tt: \implies 2 \times 2 + 2\times 0 = (2+2) v_{c} \\ \\ \tt: \implies 4 + 0 = 4 \times v_{c} \\ \\ \tt: \implies v_{c} = \frac{4}{4} \\ \\ \green{\tt: \implies v_{c} = 1 \: m/s} \\ \\ \green{\tt \therefore velocity\:of\:red\:car \:after\:collision\: is \: 1 \: m/s}$