Relative Velocity Calculation Between Two Cars Moving Westward

Calculation of Relative Velocity Between Two Cars

Two cars approach each other; both cars are moving westward, one at 71 km/h, the other at 67 km/h. What is the magnitude of the velocity of the first car relative to (in the frame of reference of) the second car? Answer in units of km/h.

Answer

Answer: 4 km/hr

Explanation

All the motion is directed westward, so we can consider west to be positive. The velocity of the first car relative to the second car is: Vr = V1 - V2 = 71 km/hr - 67 km/hr = 4 km/hr Therefore, the magnitude of the velocity of the first car relative to the second car is 4 km/hr.

Two cars approach each other; both cars are moving westward, one at 71 km/h, the other at 67 km/h. What is the magnitude of the velocity of the first car relative to (in the frame of reference of) the second car?

Answer: 4 km/hr

← Volume and mass calculation of stainless steel rectangular prism How to calculate the constant torque to stop a flywheel →