Starter – what’s the lesson Starter – what’s the lesson today?today?

+ R

+ on

circular

motioncircle

mosh

Circular MotionCircular MotionObjectivesObjectives

Be able to describe the factors that affect an Be able to describe the factors that affect an object’s motion in a circular path and give object’s motion in a circular path and give

examples.examples.

22 April 2023

Outcomes Outcomes • All should• Give examples of things that follow a circular

path and describe what forces are involved.• Most Should• Explain how an object can stay travelling in a

circular path• Some Could• Come up with their own examples of things

travelling in a circle and describe how changing some of the factors would change the motion.

• Whirling Water

• http://www.teachersdomain.org/resources/phy03/sci/phys/mfw/roller/assets/phy03_vid_roller/phy03_vid_roller_56_mov.html/phy03_vid_roller_56.mov

• Why doesn’t the water spill?

Matching centripetal forces – write these Matching centripetal forces – write these down or come up with your own examplesdown or come up with your own examples

Period of circular motionPeriod of circular motion

Frequency, f, is the number of rotations per second.FrequencyFrequency

frequency =number of rotations

time taken

i.e.

Becauseperiod =

time taken

number of rotations

T =1f

f =1T

and

Circular MotionCircular MotionPractical TimePractical Time

• Put some goggles on.• Balance a coin on the end of a coat

hanger.• Twirl.• The record is 5 coins for 5 spins! Can you

equal this?

Circular Motion - TasksCircular Motion - Tasks• 1 Draw the diagram and explain the method.

• 2 Describe the forces involved. (What keeps the coin on the end of the coat hanger?

• 3 Copy and CompleteWhen a body moves in a circle it continuously …………… towards the …………of the circle.

• This acceleration changes the …………… of motion of the body, not its …………...• The resultant force causing this acceleration is called the centripetal……………...• The direction of the centripetal force is always towards the centre of the

……………….

speed accelerates direction circle centre force

• 4 (Extension) To increase the centripetal force of an object in circular motion you could increase the _____ or ______ or decrease the ______ , whilst keeping the other two variables the same.

Wall of DeathWall of Death• http://www.youtube.com/watch?

v=31MMw3Eazqw

• Describe why the vehicles stay on the wall

Plenary - Plenary - Going Up Going Up

• – describe the lesson; what we did and what you learnt, how you learnt it; to your partner in the time it takes for a lift to reach the top floor – 120seconds.

• You may be asked to tell the rest of the class too.