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 examples of a wedge
teeth, nails, claws, knife, doorstop
Simple machines change the _______ and ________ of a force
magnitude 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.
Draw the mechanical advantage formula for 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).
What are the basic simple machines
Pulleys, levers, wedges, inclined planes, wheel and axle and screws
Draw the order of the resistance, effort and fulcrum for a first class lever
Effort, Fulcrum, resistance
Draw where the effort - resistance and fulcrum is on a third class lever
Resistance - effort - fulcrum
When you want to make a job easier, the distance (length) of the simple machine needs to be __________
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.
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 with a lever
The closer the object 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