Newtons First Law of Motion
A lesson and worksheet about Isaac Newtons First Law of Motion.
• Students will be able to state Newtons First Law of Motion.
• Students will be able to define the term inertia.
• Students will be able to give examples of Newtons First Law of Motion.
• Students will be able to define the terms friction, speed and acceleration.
4th Grade - 5th Grade - 6th Grade
Print the reading comprehension worksheet passage and questions (see below).
Students should read the passage silently, then answer the questions. Teachers may also use the text as part of a classroom lesson plan.
Sir Isaac Newton is the scientist known for stating the scientific laws by which objects move. Newton's first law of motion states that an object will remain in steady motion until a force acts upon it, and an object that is not moving at all will stay motionless (still) until a force acts upon it.
Before Newton published the first law of motion in 1687, the Italian scientist Galileo was studying motion as well. At the time, most people believed that a force was needed to keep an object traveling at a steady pace. Galileo realized that a force called friction acts against an object moving in the opposite direction. Galileo reasoned that if friction was taken away, the object would keep moving without any force needed to keep it going. In other words, the object needs a force to stop it, not to keep it going.
After Galileo died, Newton published a description of Galileo's idea about friction. This is Newton's first law of motion, also called the law of inertia. Inertia is the resistance of an object to a change in its state of motion. In other words, an object in motion will continue to move until a force is applied to slow it down or stop it. An object that is not moving will stay motionless until a force is applied to it that causes it to move. For example, when a rocket is launched, the force of the engines causes the motionless rocket to begin moving. The force created by an engine is also what puts a car in motion. The car keeps moving until a force is applied to slow it down or stop it. If you are driving a car and apply the brakes, the brakes create a force (friction) that slows the car's speed and finally stops it from moving.
Print this printable worksheet for this lesson: