Lesson 1: Intro to Newton’s Laws

This is your first face-to-face session at the Howard University Physics Lab. Please arrive on time.

Before the session:

Let’s briefly discuss the Newton’s Laws of Motion:

image1First Law:  The first law says that an object at rest tends to stay at rest, and an object in motion tends to stay in motion, with the same direction and speed. Motion (or lack of motion) cannot change without an unbalanced force acting.

image2Newton’s second law of motion:
The acceleration for a system is directly proportional to and in the same direction as the external force acting on the system an diversely proportional to its mass.

It is often written in a more familiar way:  a = F/m

The second law shows that if you exert the same force on two objects of different mass, you will get different accelerations (changes in motion). The effect (acceleration) on the smaller mass will be greater (more noticeable).

Third Law:
The third law says that for every action (force) there is an equal and opposite reaction (force). Forces are found in pairs. Think about the time you sit in a chair. Your body exerts a force downward and that chair needs to exert an equal force upward or the chair will collapse.

After the Session
Write an entry in the Reflective Journal.