When you blow some air above the upper face of a paper strip,the paper rises.This occurs because
A) the air above the upper face of the paper moves faster, which makes the pressure higher than at the lower face.
B) the air above the upper face of the paper moves faster, which makes the pressure lower than at the lower face.
C) the air above the upper face of the paper moves faster but the pressure remains constant.
D) the air above the upper face of the paper moves slower, which makes the pressure higher than at the lower face.
E) the air above the upper face of the paper moves slower, which makes the pressure lower than at the lower face.

Question

Quizplus · Accepted Answer

When air moves faster, the pressure decreases as per Bernoulli's Principle. The air moving above the paper strip creates an area of low pressure that causes the paper to rise. Therefore, the correct option is B, the air above the upper face of the paper moves faster, which makes the pressure lower than at the lower face.

When You Blow Some Air Above the Upper Face of a Paper