Two parallel nail tracks run North-South. Train A moves due north with

1.	Two parallel nail tracks run North-South. Train A moves due north with a speed of 54 kmh-1 and train B moves due south with a speed of 90 kmh-1. What is the relative speed of B with respect to A in ms-1?
Answer» V_A = 54 kmh^-1 V_B = – 90 kmh^-1 (north direction is chosen as positive) V_BA = V_B– V_A = – 90 – 54 = -144 kmh^-1 = – 40 ms^-1

Two parallel nail tracks run North-South. Train A moves due north with a speed of 54 kmh-1 and train B moves due south with a speed of 90 kmh-1. What is the relative speed of B with respect to A in ms-1?

Answer»

V_A = 54 kmh^-1

V_B = – 90 kmh^-1 (north direction is chosen as positive)

V_BA = V_B– V_A

= – 90 – 54 = -144 kmh^-1

= – 40 ms^-1