Simple Machines I
2 wheels connected by a rope, chain, or band
pulley
easier
Wheels that have teeth
Gears
These change input motion (usually rotating) to a reciprocating motion of the follower. Commonly circular or pear shaped.
This can neither be created nor destroyed. It can only be changed from one type to another.
energy
What is the formula for work?
W = ____ x _____
W = forced (F) x distance (D)
A moving inclined plane. Some examples are knives, forks, and graters.
wedge
How do we calculate gear ratio?
# teeth of driven gear / # teeth of driver gear
This type of gear greatly reduces the speed of the driven gear to which it is connected at a 90-degree angle.
worm gear
When conducting an experiment, it is important to change only of these at a time.
variable
Inclined planes wrapped around a shaft or post
screws
If two wheels are on one axle, why does the inside wheel slip when a vehicle turns?
The wheels can't turn at different speeds.
Low gears provide more ____________ but less _____________.
torque (power); speed
rack and pinion
Windmills convert ___________ energy to __________ energy.
wind energy to kinetic energy
The ratio of output to input force.
mechanical advantage
This type of pulley will cause the driven wheel to rotate in the opposite direction of the driver wheel
The type of gears that connect at an angle to change the direction of motion
Beveled gears
This mechanism can be used to prevent a gear from rotating backwards
Pawl
Name 2 of the 3 S's that explain why triangles are used to build strong structures.
support, stabilize, stiffen
What is the mechanical advantage of a pulley that is attached directly to its load below when the string is then attached to a fixed point above?
2 - the mass of the load is distributed between the two strings....twice the output force as the input force, BUT the string must moved twice as far.
The 3 classes of levers depend on the relative locations of these three elements.
fulcrum, load, effort
This configuration of gears is used to change one input force into two separate output forces
differential gearing
This connector allows rotary motion to be transferred at many different angles.
Universal joint
P = MxV
What are P, M, and V?
momentum (P), M (mass), V (velocity)