Net Force Changes an Object's Speed or Direction

Hey, I'm Atlas — and that cart in the hallway was a great experiment! Let me explain what just happened. Forces are pushes or pulls measured in Newtons (N). When MORE than one force acts on the same object at the same time, we need to find the NET FORCE — the single combined force that represents all of them together. Here's the rule: forces in the SAME direction add together. Forces in OPPOSITE directions subtract. If I push the cart forward with 40 N and you push it backward with 25 N, the net force is 40 − 25 = 15 N forward. The cart moves forward, but slower than if you weren't pushing back. When the net force is ZERO — meaning all the forces perfectly cancel out — we call that BALANCED forces. A balanced force means NO change in motion. The cart either stays still or keeps moving at the exact same speed in the same direction. When the net force is anything OTHER than zero, forces are UNBALANCED. An unbalanced net force always changes the object's motion — it accelerates. Accelerate means the object speeds up, slows down, or changes direction. All three count as acceleration. For the same object, a bigger net force produces more acceleration; a smaller net force produces less acceleration. A heavier object needs a larger net force to reach the same acceleration as a lighter one — that's also part of Newton's Second Law. Direction of the net force is the direction the object accelerates. Hint: draw arrows for each force, label the size in Newtons, then combine them. Same direction? Add. Opposite? Subtract. Whatever is left over is your net force.