This document discusses different types of forces including air resistance, upthrust, electrostatic, magnetic, gravitational, and nuclear forces. It provides examples of how upthrust allows boats and other objects to float by balancing the upward force of upthrust against the downward force of gravity. It also explains Hooke's law which states that the extension of a spring is proportional to the applied force.

2.  List the types of forces.
 Identify the forces.
 Difference between balanced and unbalanced
force.
 State the Hooke’s law

3.  air resistance
 upthrust
 electrostatic
 magnetic
 gravitational
 nuclear forces

4. 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.

5. Which bunny will fall to the ground quickest and
why?
1
2

6. 2
1
Loser !
Roadkill !
Bunny 1 will hit the ground
sooner due to decreased air
resistance. However bunny 2
will have a smoother landing.

7. 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.

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

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

11. What forces do you think are working here?
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

15. Hooke’s law
states that the
extension of the
spring is
proportional to
the force.
 HOOKE”S LAW

16. The forces between the charge is called
electrostatic force
By Friction
 Electrons (-) only are able to travel