Lesson 16 Perpetual Motion and Mechanics of Movement

Topic : Inclined Planes

Why do we use inclined planes ? in machines

• Allows us to exchange effort for distance (reduce effort increase distance)

• It looks cool and occurs naturally

• Allows us to reduce the amount of effort we need to exert

Which of these makes use of levers ?

• 
• 
• 
• 

Between nails and screws which are more permanent joining pieces of material together ?

• Nails

• Screws

Which of these systems use centrifugal force to function?

• Gyroscope

• Car Seat belts

• Friction Drive Toy

• Bicycle

Which stores more energy for a spring?

• A spring squeezed to half its normal length

• A spring stretched to double its normal length

• A spring at rest

• A spring stretched to 3 times its normal length

What is friction?

• The force holding us down to the ground

• resistant force due to one object rubbing against another

• resistant force due to the electromagnetic interaction of the earth

• The spring force described through Hooke's Law

What is the main beneficial use of friction in transport?

• Provide heating for the vehicle

• Helps a vehicle accelerate

• Helps a vehicle to slow down

• Absolutely nothing

Which situation has the largest amount of friction associated to it ?

• driving a car at 100 + km/h on the road

• Walking on ice

• Skating on ice

• driving a car on ice at 100 + km/h

What is the net force on the block ? (moving right is +ve)

• 700 N

• 300 N

• - 300 N

• 500 N

Which of these systems benefit from air resistance?

• person parachuting down

• walking through the rain with an umbrella

• sail boats

• Trying to get home on a windy day