Test: Balanced and unbalanced forces - Year 8 MCQ

100g = 0.1kg, and weight on Jupiter is 0.1kg × 25 N/kg = 2.5N. Weight depends on the gravitational force acting on the mass.

Mass is not a force; it is a measure of matter measured in kilograms or grams. Gravity, pull, and weight are forces, as they involve interactions that can cause acceleration.

When two forces of equal magnitude act in opposite directions on an object, they cancel each other out. This results in a net force of zero, meaning the forces are balanced.

Unbalanced forces always cause a change in the state of motion of an object. This change can include speeding up, slowing down, or changing direction. The statement "They have no effect on an object" is NOT true because unbalanced forces do affect the object by changing its motion.

If an object is accelerating, it means there is a net force acting on it in the direction of its acceleration. Therefore, the forces acting on the object are unbalanced.

According to Hooke’s Law, the stretch of a spring is proportional to the force applied (F = -kx). Therefore, the larger the force, the greater the stretch. Additionally, per Newton’s Third Law, the mass and spring exert equal and opposite forces on each other, ruling out options C and D.

When forces acting on an object are balanced, the object experiences no net force. According to Newton's First Law of Motion, the object will continue in its current state of motion, which could be at rest or moving with a constant velocity.