science 1-3 Flashcards
Gear
rotating wheel-like object with teeth around its rim.
Sprocket
A gear that fits into the links of a chain
Fixed
something that is attached to something that doesn’t move, or it can’t move at all.
Moveable
a pulley attached to something movable, such as a construction crane or oil derrick
Pulley
a wheel with a grooved rim to guide a rope or chain that runs along the groove; used to transmit or change the direction of force.
(The more pulleys you use , the more mechanical advantage you get, but the final pulling down motion doesn’t increase the mechanical advantage.)
Mechanical advantage
the ratio of the force produced by a machine or system (the load) to the force applied to the machine or system
Efficiency
the ratio of the useful work or energy provided by a machine or system to the actual work or energy supplied to the machine or system
Ramp
A slope or inclined plane used for joining two different levels.
Fulcrum
the point of the lever that doesn’t move
Wheel and axle
a machine consisting of two turning objects attached to each other at their centres. One object causes the other to turn.
Lever
a machine consisting of a bar that is free to rotate around a fixed point, changing the amount of force that must be exerted to move an object
What is the function of simple machines (what do they do?)
Make life easier and more convenient, they allow us to lift heavy things more easily, move things faster and more efficiently, and allow more complex machinery to work. They make work easier by changing the force, distance, and direction of the things needed to do
What is a Joule equal to
When you lift 1 N a distance of 1 m is equal to 1 joule
Know some examples of simple machines
A pulley is an example is a weight machine
A wheel and axle, an example, is a wheel on your car
A lever and inclined plane, such as a teeter-totter
Screw an example is a light bulb
A wedge is an example is an axe
What is the definition of work, and how do you know when work is being done
Work is the transfer of energy through motion. You know work is being done when you exert a force on an object and move that object some distance in the direction of the force; you do work on the object.
explain class 1,2,3, levers
class 1: the fulcrum is in between the load and the effort
class 2: the load is between the fulcrum and the effort
class 3: the effort is between the fulcrum and the load
work formula
W=FD
Mechanical advantage formula
MA = FL(load force)/FE(effort force
or
MA = effort arm/load arm
what are all the simple machines that we are needing to know
levers, inclined planes, wedge, winch, pulleys, screw/spiral, wheel and axle, gears/sprockets,
note: pulling down doesn’t give mechanical advantage
walking horizontal with weight doesn’t affect work
what is kinetic energy and potential energy
kinetic energy is the energy of motion
while
potential energy is the energy stored before becoming kinetic or a different kind of energy(the pre-energy)
efficiency formula
E = WL/WEF x 100%
what are ways simple machines make things easier
changes force required, changes direction of force, reduces friction,
