List the types of forces. Identify the forces. Difference between balanced and unbalanced

force. State the Hooke’s law

air resistance upthrust electrostatic magnetic gravitational nuclear forces

Air resistance is an example of friction. It is the resistance of the air to things moving through it.

Streamlined objects easily push the air out of the way. They have a low air resistance.

Objects that are not streamlined have a high air resistance.

Air cannot flow around them and this can cause turbulence.

Which bunny will fall to the ground quickest and why?

12

2

1

Loser !

Roadkill !

Bunny 1 will hit the ground sooner due to decreased airresistance. However bunny 2 will have a smoother landing.

What’s upthrust?

Upthrust is a force that only exists in liquids, such as lakes, oceans, swimming pools and even cups of tea!

It is a push that always goes straight up, against the direction of gravity.

It pushes UP! That’s why it’s

called Upthrust.

Upthrust in action

This boat has gravity pushing it down, and the upthrust of the water pushing up.Because the forces are balanced, the ship floats.

Upthrust

Gravity

More examples of upthrust

If you let go of your drinking straw, it floats up and sometimes tries to bob out of the glass!

normal reaction forces at the wheels, the upward push on the car from the ground

push on the car by the man

friction opposing the motion

weight, the downward pull of gravity on the car

What forces do you think are working here?

Hooke’s law states that the extension of the spring is proportional to the force.

HOOKE”S LAW

By Friction

Electrons (-) only are able to travel

The forces between the charge is called electrostatic force