If a particle moves with velocity V PA = (2.0 m/s) + (4.0 m/s) relative to frame A, what is the velocity V AP of the frame relative to the particle?

Question

a. -(2.0 m/s) + (4.0 m/s)


b. -(2.0 m/s) - (4.0 m/s)


c. (2.0 m/s) + (4.0 m/s)

Answer 1

I'm going to make the assumption that this is in vector unit notation and that this is a two dimensional problem.

If particle P is moving 2.0m/s(i) + 4m/s(j) with respect to particle A then particle A should appear to be moving -2.0m/s(i) - 4.0m/s(j). This can be imagined by assuming that one particle is stationary and finding the motion of the other particle relative to that particle.

Particles in motion appear to be stationary in their reference frame so everything else seems to move relative to them. Therefore if particle A sees particle P moving at a magnitude of 4.4m/s relative to itself. P may view the same system such that particle particle A, relative to particle P, moves at -4.4m/s magnitude, or choice B.