Two particles are projected from the same point with the same speed in the same vertical plane at different angles with the horizontal. A reference frame is fixed to one particle. Which statements about the position vector r of the other particle in this frame are correct?
Select all that apply

Question

Two particles are projected from the same point with the same speed in the same vertical plane at different angles with the horizontal. A reference frame is fixed to one particle. Which statements about the position vector r of the other particle in this frame are correct?

Select all that apply

G1 Physics · Accepted Answer

Both particles have the same gravitational acceleration, so their relative acceleration is zero. Initially they are at the same point, hence r=(u₂-u₁)t. The relative velocity u₂-u₁ is constant, so the direction of r remains fixed and its magnitude increases linearly with time. Hence only option C is correct. The printed source key appears inconsistent.