Transcript Robot Physics

Robot Physics
MVRT
2011 – 2012 Season
Overview
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Mass vs. Weight
Velocity
Force
Torque
Mass vs. Weight
• MASS DOES NOT = WEIGHT
• Mass
– The amount of matter/stuff that makes up an object
• Weight
– The force of gravity acting upon an object
• Ex.
– You weigh less on the moon but you have the same
amount of matter within you
Velocity
• Speed
– How long it takes an object takes to travel a
certain distance
• Velocity
- Speed with direction
Car A
Car B
Car A travels a smaller
distance in the same time so
car A has a slower speed
Acceleration
• Acceleration is the change in velocity and there
are two types of acceleration
– when an object moves forward and slowly increasing
its speed that is acceleration
– when a motor is spinning it is constantly changing
direction and as it goes faster and faster it is
accelerating
Force
• Forces change the speed of an object
• There are many forces ex:
– Friction
– Torque
• Two factors determine it:
– Mass - how much stuff is in something
– Acceleration – how much the speed of the object
changes
Friction
• When something is moving across a
surface, friction prevents it from sliding
• Activity:
– Move two objects across the gravel outside
and on the tile floor
– Heavier = harder = more friction = can’t get
pushed around
Torque
• Torque gives more power for less
energy(Is that right) but the tradeoff is that
the max speed is really low
• Speed allows you to go really fast but it
takes more energy to start (more taxing on
the person to pedal especially uphill)
Torque Activity
• Activity one:
– Drag race idea
– Have 2-3 people race across the parking lot with the rest
watching forming a hypothesis based on what they have learned
• Activity two:
– Bring in a bike and show that one pedal in low gear = 1 rotation
(or very few)
– Show that one pedal in high gear = more than one rotation(but
harder to start)