steady motion
Post on 16-Feb-2016
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Steady Motion
How do objects move at a steady speed?
Starter:
Describe the forces acting on a car moving at a steady velocity of 60mph, forwards.
Revision card
• Make a revision card for momentum.
6 mark question
• Use the idea of momentum to explain why cars are built with crumple zones.
Marks SPAGWhat a crumple zone is/ where they are on a car.How a crumple zone reduces the force on a person.Use of the correct momentum equation.What happens if no crumple zone.
Learning Outcomes
1) explain that, when an object travels at a steady velocity, there is no change of momentum.
2) explain that no resultant force is required to keep an object moving in a straight line at a steady speed
Speed – Time – graph
For each of the 4 stages, draw a force diagram to show what is happening.
A
BC
D
Time
Speed
Mini Plenary worksheet.
explain that no resultant force is required to keep an object moving in a straight line at a steady speed
What are these strange people trying to do?
• Curling
On the floor
On Ice
On “perfect” ice the kettle never stops, it stays at a steady speed. Why?
Lets investigate -
• Which surface is closest to “perfect ice”?
Surface Force needed to move object (N)
Steady Speed and Momentum
• Look at the equations for momentum and work out why at a steady speed, momentum of an object does not change.
6 mark question
• Use the idea of momentum to explain why cars are built with crumple zones.
Marks SPAGWhat a crumple zone is/ where they are on a car.How a crumple zone reduces the force on a person.Use of the correct momentum equation.What happens if no crumple zone.
Round the Room Questions
Task
• Write 5 momentum questions of your own, and produce a marking scheme.
• Swap with neighbour, complete their questions and WWW/ EBI them.
Look at the objectives – how are we doing?
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