Which example illustrates Newton’s first law?
A. The force of a wheelbarrow on the ground is equal to the force of the ground on the wheelbarrow.
B. More mass is added to a wheelbarrow, and a larger force is required to move it.
C. A person pushes a wheelbarrow, causing it to move forward.
D. The force of a wheelbarrow on the ground is in the opposite direction of the force of the ground on the wheelbarrow.
The Correct answer and Explanation is :
The correct answer is C. A person pushes a wheelbarrow, causing it to move forward.
Explanation:
Newton’s First Law of Motion, also known as the law of inertia, states that an object at rest will remain at rest, and an object in motion will continue in motion at a constant velocity in a straight line unless acted upon by an external force. This principle highlights the concept of inertia, which is the tendency of an object to resist changes in its state of motion.
In option C, when a person pushes the wheelbarrow, they are applying an external force to overcome the wheelbarrow’s inertia. Initially, the wheelbarrow is at rest, and it will remain at rest unless a force acts on it. The push from the person provides that force, allowing the wheelbarrow to move forward. This example effectively illustrates Newton’s First Law because it shows how an object (the wheelbarrow) requires an external force (the push from the person) to change its state from rest to motion.
In contrast, the other options focus on different aspects of Newton’s laws.
- A discusses action-reaction forces (Newton’s Third Law), where the forces exerted by the wheelbarrow and the ground on each other are equal and opposite.
- B relates to Newton’s Second Law, which states that the acceleration of an object depends on the net force acting upon it and its mass. Adding more mass to the wheelbarrow means more force is needed to achieve the same acceleration.
- D also addresses action-reaction forces, similar to A, indicating how forces act in opposite directions.
In summary, option C is the only example that directly illustrates the principle of inertia defined in Newton’s First Law, demonstrating the necessity of an external force to change an object’s state of motion.