Materials

• Leaf blower
• Toilet paper
• Dowel rod

Instructions

• STEP 1: Place the toilet paper on the dowel rod and unroll a few pieces.
• STEP 2: Hold the dowel rod horizontally so the roll will unroll away from you.
• STEP 3: Turn on the leaf blower and aim the stream of air just over the top of the toilet paper. Provide evidence of the effects of balanced and unbalanced forces on the toilet paper.
• STEP 4: Place another roll of toilet paper on the dowel rod. Turn on the leaf blower at a higher speed and aim the fast flow of air in different directions over the top of the toilet paper. Compare the effects of different strengths or different directions of pushes and pulls on the motion of the toilet paper.

Explanation

Bernoulli's Principle states that the pressure exerted by a fluid decreases as its velocity increases. Increasing the velocity over the top surface of the toilet paper lowers the pressure of the air pushing down on the paper. The paper is lifted because there is an unbalanced force of air pressure acting upward.