Question

question 1 of 10 the diagram below shows the velocities of two runners. 10 m/s west runner 1 7 m/s east runner 2 from the frame of reference of runner 2, what is the velocity of runner 1? a. 17 m/s west b. 17 m/s east c. 3 m/s west d. 3 m/s east

Explanation:

Step1: Define positive - direction

Let the east - direction be positive. Then the velocity of runner 1, $v_1=- 10\ m/s$ (negative because it is west - ward) and the velocity of runner 2, $v_2 = 7\ m/s$.

Step2: Use relative - velocity formula

The relative velocity of runner 1 with respect to runner 2 is $v_{12}=v_1 - v_2$.
Substitute the values: $v_{12}=-10 - 7=-17\ m/s$.
The negative sign indicates the direction is west.

Answer:

A. 17 m/s west