Balanced and Unbalanced Forces

Objectives:

• Students will be able to define balanced and unbalanced forces.

• Students will be able to identify Newtons law of motion.

Suggested Grades:

4th Grade - 5th Grade - 6th Grade

Lesson Procedure:

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.

Lesson Excerpt:

Suppose you are traveling in a car along a freeway at a constant speed of 60 miles per hour. In order to keep the car moving at that speed, the car's engine applies a force. If a force is being applied to the car, why doesn't it start to move faster? The reason is that the force being applied to the car is balanced by an equal force of friction being applied in the opposite direction. The two forces cancel each other out, and the car's speed remains constant. This is an example of a balanced force.

Now suppose the force being applied to the car is increased so that it is greater than the force being applied by friction in the opposite direction. The car will begin to move faster. This is an example of an unbalanced force. Another example of an unbalanced force would occur if the car's brakes were applied. This would increase the force of friction, and the car would slow down and eventually stop.

Continued...