Question

At the same moment, one rock is thrown upward at 4.5 m/s and another thrown downward at 3.4 m/s. What is the relative velocity of the first rock from the perspective of the second rock? Assume that up is positive.

Answer 1

so we can assume the first rock is stationary, by adding the top rocks velocity, to the bottom one, therefore, we have -10.7 ms-1, from the perspective of the first rock, hope this helps