posted by Lee .
A particle leaves the origin with a velocity of 7.2 m/s in the positive y direction and moves in the xy plane with a constant acceleration of (3.0 – 2.0 ˆi ˆj ) m/s2. At the instant the particle moves back across the x axis (y = 0), what is the value of its x coordinate?
susan drops a ball, and 2 second later the ball has a speed of 20m/s. what is the ball's acceleration?