Two cars start at the same point,but travel in opposite directions on a circular path of radius R,each at speed v.While each car travels a distance less than $\frac { \pi } { 2 } \mathrm { R }$ ,one quarter circle,the center of mass of the two cars A)remains at the initial point. B)travels along a diameter of the circle at speed v' v. E)remains at the center of the circle.

Question

Two cars start at the same point,but travel in opposite directions on a circular path of radius R,each at speed v.While each car travels a distance less than $\frac { \pi } { 2 } \mathrm { R }$ ,one quarter circle,the center of mass of the two cars
A)remains at the initial point.
B)travels along a diameter of the circle at speed v' < v.
C)travels along a diameter of the circle at speed v' = v.
D)travels along a diameter of the circle at speed v' > v.
E)remains at the center of the circle.

Quizplus · Accepted Answer

The center of mass of the two cars moves along the diameter of the circle at a speed less than v because the cars are moving in opposite directions, reducing the net speed of the center of mass.

Two Cars Start at the Same Point,but Travel in Opposite π2R\frac { \pi } { 2 } \mathrm { R }2π​R

Two Cars Start at the Same Point,but Travel in Opposite $\frac { \pi } { 2 } \mathrm { R }$