Air Resistance

Air Resistance

What is the name of the force that makes him fall?

• Gravity

• Name one thing you think could help him in this situation?

A parachute!

• With a parachute, they will not be travelling very fast when they hit the ground.

• They are falling through the air and another force is acting on them.

• This force is called air resistance.

Balanced Forces

• As gravity pulls the man down, air pushes upwards inside the parachute

• There are two forces acting on the man . He falls at a safe speed because the forces pull in opposite directions so they cancel each other out.

• The two forces are balanced

What is the name of the force pushing the man's face?

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Does the size of a parachute matter? Why?

• It is very easy to wave your hand through the air. This is is because the air is a thin substance.

• This means parachutes need to cover a big area. A small parachute will not experience enough air resistance and a parachutist will fall

Would a parachute be a good idea on the moon?

Air resistance and friction

• Air resistance is like friction. It slows things down

• A large area gives a lot of air resistance. The thistle uses air resistance to make its seed float far away on the wind

• The plane is designed to move smoothly through the air with very little air resistance. This type of shape is called streamlined

Which design is streamlined?

Which car could drive faster?

Multiple Choice

Look at the pictures of the cars. Which car will have the most air resistance force acting upon it? They will be moving at the same speed.

• All will have equal air resistance force.

Multiple Choice

When dropped from the same distance, which will fall to the floor faster?

Multiple Choice

The more streamlined an object is, the...

• More air resistance

• Less air resistance

• Slower air resistance

• Faster air resistance

Multiple Choice

Air resistance is a force caused by...

• Water pushing against moving objects

• Air pushing against moving objects

• Gravity pushing against moving objects

• Normal force pushing against moving objects

Multiple Choice

Which has more air resistance?

Multiple Choice

Air resistance pushes against falling

objects and __________________.

• Speeds them up

• Keeps them afloat

• Slows them down

• Spins them

Multiple Select

Which two of these forces act on parachutes?

• Air Resistance

• Gravity

• Thrust

• Kinetic Energy