PHYSICS · Multi-part · CBSE · Physics · Laws of Motion · Laws of Motion
Problem
Four identical carts, W, X, Y, and Z (each of mass 2.0 kg), roll along a straight, horizontal track. A data‐collection device attached to each cart reports the magnitude and direction of all horizontal forces acting on that cart at one instant. The measured forces and the carts’ current directions of motion are given below (positive direction is to the right).
• Cart W: Forces = 3 N right, 5 N left; Moving right
• Cart X: Forces = 4 N right, 2 N left; Moving left
• Cart Y: Forces = 6 N left, 1 N right; Moving left
• Cart Z: Forces = 8 N right, 8 N left; Moving right
(a) For each cart, indicate the direction of the net horizontal force.
(b) Rank the carts from greatest to least according to the magnitude of their acceleration. If any carts tie, state that explicitly.
(c) For each cart, state whether the acceleration is in the same direction as the cart’s velocity, opposite to it, or zero. Justify each answer briefly in terms of forces and Newton’s second law.