SAIL into STEM Friction using Car and Ramp and the Engineering Design Cycle.

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Transcript of SAIL into STEM Friction using Car and Ramp and the Engineering Design Cycle.

Page 1: SAIL into STEM Friction using Car and Ramp and the Engineering Design Cycle.
Page 2: SAIL into STEM Friction using Car and Ramp and the Engineering Design Cycle.

SAIL into STEM

Friction using Car and Ramp and the

Engineering Design Cycle

Page 3: SAIL into STEM Friction using Car and Ramp and the Engineering Design Cycle.
Page 4: SAIL into STEM Friction using Car and Ramp and the Engineering Design Cycle.

Learning Goals

Use technology to measure and describe forces acting on a car in motion.

Define friction.Distinguish among various types of friction.

Design a sail car that will slow down or speed up a car undergoing friction

Explain applications of friction.

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Friction Friction is a force that resists the

motion of objects or surfaces. Many kinds

of friction exist.

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Friction

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Defining a “system”First we need to see how a car responds to unbalanced forces and identify the types of friction.

Set up your equipment and let’s see what we variables we can control.

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Setting up the experiment

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Friction and two surfaces Friction depends on both of the surfaces in

contact.

When the hockey puck slides on ice, a thin layer of water between the rubber and the ice allows the puck to slide easily.

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Friction and energy

Each time two moving surfaces touch each other, tiny bits of material are broken off by friction.

Breaking off bits of material uses energy.

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Identifying friction forces

Friction is a force, measured in newtons just like any other force.

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Sliding friction is a force that resists the motion of an object moving across a surface.

Identifying friction forces

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Collect Data

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Create the “Sail Car”

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Make a hypothesis

If the sail is affected by air friction, then the car’s speed will:

a) slow down by ______ %

b) speed up by ______ %

c) stay the same

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Collect Data for “Sail Car”

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Analyze any % change in Average Speed due to Air

Friction% increase = Trial 1 – Trial 2 x 100%

Trial 1

% decrease = Trial 2 – Trial 1 x 100% Trial 1

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Friction and energy

Friction changes energy of motion into heat energy.

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Reducing the force of friction

Unless a force is constantly applied, friction will slow all motion to a stop eventually.

It is impossible to completely get rid of friction, but it can be reduced.

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Using friction

Friction is also important to anyone driving a car.

Grooved tire treads allow space for water to be channeled away from the road-tire contact point, allowing for MORE friction in wet conditions.

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Using friction Shoes are designed

to increase the friction between their soles and the ground.

How do you think these shoes increase friction?

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Modify your “Sail Car”

Use materials to make modifications to the sail.

Increase your friction by 10% or decrease your friction by 10%