Simple Machines
What do simple machines do?
Make jobs easier
LANDMINE
Lose 100 points
Give an example of a screw that you can find around your house
lightbulb, screw, bottle cap
An inclined plane with a long surface will have a ________ angle of incline
The job will be _____________.
small
easier
Name 3 everyday examples of a wedge
teeth, nails, claws, knife, doorstop
Simple machines change the _______ and ________ of a force
magnitude (size) and direction
DOUBLE POINTS: Define magnitude
Give an example of a second class lever
Examples: Sweeping using a broom; standing on tip toes; flexing elbow or knee joints, etc.
State the formula used to calculate the mechanical advantage of a lever
MA = load/effort
An inclined plane with a short surface will have a _______ angle of incline.
The job will be _______.
big
harder
DOUBLE:
A mechanic uses a crowbar to lift a heavy rock. The load is 150 N and the effort applied is 30 N.
Calculate the mechanical advantage (MA).
5
What are the basic simple machines
Pulleys, levers, wedges, inclined planes, wheel and axle and screws
State the order of the load, effort and fulcrum for a first class lever
Effort, Fulcrum (in the middle), Load
or
Load, Fulcrum (in the middle), Effort
State where the effort, load and fulcrum are on a third class lever
Load - Effort (middle) - Fulcrum
or
Fulcrum - Effort (middle) - Load
When you want to make a job easier, the distance (length) of the simple machine needs to be __________
larger
A student uses a lever to lift a 120 N load using an effort force of 30 N.
Calculate the mechanical advantage (MA) of the lever.
4
A nut cracker is which class lever?
Second class
100 more points: DRAW the fulcrum, resistance and effort arm on the board
How does the size of the wheel affect the speed at which an axle turns?
A larger wheel will make the axle turn more slowly
When picking up a sausage, a pair of tongs has a mechanical advantage of 3 and an effort force of 25N.
Calculate the load of the sausage .
75N
Pulleys make it possible to _______ and _________ loads.
raise
lower
Give an example of a pulley in real life.
Window blinds, cranes, wells
The point on a lever that does not move
Fulcrum
Provide two examples of an inclined plane.
Examples: slide on playground; handicapped ramp; a ladder; a roller coaster ride (track).
Describe how the position of the fulcrum affects the effort needed to lift an object (load) with a lever
The closer the object (load) is to the fulcrum, the less effort is needed.
What happens when 2 or more pulleys are used together?
It increases the force to make it 2 times easier.
A lever has a mechanical advantage of 4 and a bookshelf is 160 N.
Calculate the effort needed to lift the bookshelf using the lever.
40N