Newton's First Law of Motion

Newton's First Law

• An object at rest remains at rest and an object in motion remains in motion at a constant velocity, unless acted upon by an unbalanced force.
• The natural state of an object is to move at a constant velocity, not to come to rest on its own.
• Friction is an example of an unbalanced force that can stop an object, such as a shopping cart.

Space and Constant Velocity

• In the absence of forces, an object in space will keep going at a constant velocity, almost forever.
• The example of throwing a baseball in space illustrates this concept.

Mini Physics Lab 1

• The lab demonstrates Newton's First Law using an index card, a mug, and pennies.
• When the card is flicked, the penny falls into the mug due to the unbalanced force of gravity.
• The normal force of the card is removed, causing the penny to accelerate downwards.

Balanced and Unbalanced Forces

• Before the card is flicked, the penny has two balanced forces: gravity and the normal force.
• When the card is removed, the forces become unbalanced, and the penny falls.

Mini Physics Lab 2

• The lab demonstrates the difficulty of achieving a state of rest in an object.
• The marble is blown by two people using straws, and it is hard to keep it stationary.
• This shows that an object at rest is an unusual state, requiring an unbalanced force to be applied and then balanced again.