review part 2

What happens to pressure in a fluid according to Pascal’s Principle?

• It stays the same everywhere

• It decreases with height

• It is transmitted equally in all directions

• It moves toward the source of force

Answer explanation

According to Pascal's Principle, pressure applied to a confined fluid is transmitted equally in all directions. This means that any change in pressure at one point in the fluid is felt throughout the entire fluid.

Which principle explains how airplanes achieve lift?

• Pascal’s Principle

• Newton’s Second Law

• Bernoulli’s Principle

• Archimedes’ Principle

Answer explanation

Bernoulli’s Principle explains lift by stating that as the speed of air over the wing increases, the pressure decreases. This pressure difference creates an upward force, allowing airplanes to achieve lift.

What does a hydraulic system use to change a force?

• Air pressure

• Heat

• Pressurized fluid

• Magnetism

Answer explanation

A hydraulic system uses pressurized fluid to transmit force. This allows for the multiplication of force, making it effective for lifting heavy loads and operating machinery.

What is the unit for measuring force in physics?

• Joule

• Pascal

• Newton

• Watt

Answer explanation

The unit for measuring force in physics is the Newton. It is defined as the force required to accelerate a one-kilogram mass by one meter per second squared, making it the correct choice among the options provided.

Tags

NGSS.MS-PS2-1

NGSS.MS-PS2-2

According to Bernoulli’s Principle, as the speed of a fluid increases, the pressure...

• Increases

• Stays the same

• Decreases

• Becomes zero

Answer explanation

According to Bernoulli’s Principle, an increase in fluid speed results in a decrease in pressure. Therefore, as the speed of a fluid increases, the pressure decreases.

When you blow across a paper, it lifts upward because...

• Gravity pulls it

• Pressure below the paper is greater

• Air pushes it from behind

• The paper becomes lighter

Answer explanation

When you blow across the paper, the air pressure above it decreases, while the pressure below remains higher. This pressure difference causes the paper to lift upward.

Why does pressure increase with depth in a fluid?

• Molecules rise to the top

• Gravity pulls the fluid downward

• The shape of the container changes

• Fluid density decreases

Answer explanation

Pressure increases with depth in a fluid because gravity pulls the fluid downward, causing the weight of the fluid above to exert more force on the fluid below, resulting in higher pressure at greater depths.

What creates the downward force on a race car’s spoiler?

• Lift

• Drag

• Decreased air pressure

• Increased air pressure above

Answer explanation

The downward force on a race car's spoiler is created by increased air pressure above the spoiler. This pressure difference generates downforce, enhancing traction and stability during high-speed racing.

Tags

NGSS.MS-ETS1-1

Which part of a hydraulic system provides the increased output force?

• Input piston

• Fluid reservoir

• Output piston with larger area

• Vacuum pump

Answer explanation

The output piston with a larger area generates greater force due to Pascal's principle, which states that pressure applied to a confined fluid is transmitted undiminished. This results in an increased output force compared to the input.

Explain why the top of a wing has lower pressure than the bottom.

• Because it is flatter

• Air moves slower on top

• Air moves faster on top, reducing pressure

• Heat escapes from the top

Answer explanation

The top of the wing has lower pressure because air moves faster over it compared to the bottom. According to Bernoulli's principle, faster-moving air results in lower pressure, creating lift.