Draw a free body diagram of an apple falling from a tree.
refer to the board for the answer.
What is a force?
which person is heavier?
Person A
reaches from a cloud down to earth?
electric
what force lets you throw a spear?
applied
Identify the two forces
air resistance
Gravity
If forces acting on a ball are unbalanced, what happens?
what can make a see-saw balanced?
both people weighing the same amount. moving along the see-saw to different point from the fulcrum.
has a north and south pole. non contact force
magnetic
what force means you dont sink into the earth when standing still?
normal force
Draw a free body diagram of a feather falling in a vacuum.
Non-contact forces include:
How can these two people balance the see-saw without touching the ground?
person A can move closer to the fulcrum.
what force is on a plane flying through the sky.
gravity, applied (thrust), air resistance
If the air gets thinner as you go higher (thinner air = less air particles), explain why planes fly high rather than closer to the ground.
to reduce resistance and save fuel.
Which way would this object move and why?
to the left, as the applied force is greater than the friction force.
A student is dragging a tyre in the sports centre for fitness. Mr O’Neill suggests they make it harder by going out to the concrete to try it. Why?
A) Concrete is rougher than the polished floor, so friction will be greater.
B) The concrete has spring force.
C) It is hot outside so gravity is stronger.
D) Concrete is rougher than the polished floor, so friction will be less.
A) Concrete is rougher than the polished floor, so friction will be greater.
If a feather and a bowling ball fall in a vacuum, what is the force that is missing that allows them to fall at the same time.
air resistance ( a vacuum has no air particles)
What forces slow down a ball thats been thrown into the air?
air resistance, gravity
A glider has no engine but can remain in the air flying for long periods. how does it do this?
uses air resistance and its clever wing design to keep in airborne.
Will this rocket get off the ground?
yes as the applied force is greater than gravity. seen in the longer arrow.
A book is sitting on the desk. A clumsy teacher walks past and knocks the book onto the floor.
What new force starts acting on the book once it is falling?
Gravity
Air resistance
Normal force
Magnetism
Air resistance
what is the net force on this object?
100 - 100 = 0
slowing a bullet going from the air to the water.
explain the direction of movement of a box pushed to the left with 100 N force, friction pushing right with 70N force, gravity 10 N and normal 10 N.
10 - 10 = 0 so it will not float or sink
100 - 70 = 30 to the left.
it will be pushed left.