Perfect! In Case 2, the cars are moving towards each other, so, the accident will have a greater impact. The important quantity involved here is

**relative velocity**between two objects.Let \(v_{\text{AB}}\) represent the velocity of

An important equation is \(v_{\text{AB}} = -v_{\text{BA}}\). So, if A is moving at \(10 \, \mathrm{km/h}\) towards B, B is moving at \(- 10 \, \mathrm{km/h}\) towards A.

**A wrt B**. For example, if a car is travelling at \(40 \, \mathrm{km/h}\) towards the East, we can say that \(v_{\text{CE}} = 40 \, \mathrm{km/h}\). Here,**C**is the**Car**and**E**is the**Earth**.An important equation is \(v_{\text{AB}} = -v_{\text{BA}}\). So, if A is moving at \(10 \, \mathrm{km/h}\) towards B, B is moving at \(- 10 \, \mathrm{km/h}\) towards A.

We said that the velocity of the Car wrt Earth, \(v_{\text{CE}}\) is \(30 \, \mathrm{km/h}\). What is \(v_{\text{EC}}\)?

\(30 \, \mathrm{km/h}\)

\(-30 \, \mathrm{km/h}\)

\(0 \, \mathrm{km/h}\)

\(60 \, \mathrm{km/h}\)