Isaac Newton was an English mathematician, astronomer, and physicist. His famous laws of motion helped to explain an object’s motion. Newton’s First Law of Motion states that an object at rest stays at rest unless acted upon by an unbalanced force. Additionally, an object in motion stays in motion at the same speed and direction unless acted upon by an unbalanced force. An unbalanced force changes an object’s motion and/or direction. Newton’s First Law is also known as the Law of Inertia. Inertia is the resistance of an object to a change in its motion. In the image, the apples continue travelling forward even when the cart is stopped by the barrier.

Question

What kind of force must act on an object at rest in order to move it (as stated in Newton’s first law)?

What kind of force could change a moving object from its same speed and direction?

Answer 1

To move an object at rest, an unbalanced force must act upon it. This force can come from various sources, such as a push or pull, friction, or gravity.

To change a moving object from its same speed and direction, it also requires an unbalanced force. This could be due to a variety of factors, such as friction, a collision with another object, or an applied force that alters the object's motion or direction.