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Gr 8 Unit B
Mechanical System Chapter 5
Question | Answer |
---|---|
What are the 3 types of levers? | Class 1:Fulcrum is in the middle. Class 2: Output is in the middle. Class 3: Input is in the middle. |
How do you find the efficiency percentage? | Wout/Win x 100% =mass in J/the amount of work used in J =decimal =to percent |
How do you calculate the Mechanical Advantage of a simple machine? | is output force/input force (output Divided by input) |
What are the 6 simple machines? | Wedge, Screw, Inclined Plane, Lever, Pulley, Wheel and Axle |
How do you increase the efficiency of a simple machine? | When you use a pulley, you may hear the pulley squeak sound energy and it may become warm heat, this is the work done by friction. If you reduce the frictional force, you increase the efficiency of a machine. To reduce friction is to add grease or oil. |
How do you calculate ideal mechanical advantage for an inclined plane? | Length of Ramp/Height of Ramp (Length of Ramp Divided by Height of Ramp) |
Why is the output work of a simple machine always less than the input work? | The output work is always less than the input work because some of the energy put into using the machine converts into other forms of energy, such as heat, due to friction. |
How do you calculate the ideal mechanical advantage of a pulley? | The ideal mechanical advantage of a pulley is the amount of support ropes that are being pulled in the opposite direction of the pulley system. |
How do you calculate the ideal mechanical advantage when the load is attached to the wheel? | radius of wheel/radius of axle |
How do you calculate the ideal mechanical advantage when the load is attached to the axle? | radius of axle/radius of wheel |
How do you calculate the ideal mechanical advantage of a lever? | length of the input arm/length of output arm |
What is a simple machine? | A simple machine is a machine that requires the application of a single force to do work. |
What is a mechanism? | A mechanism is made up of several different types of machines that work together to perform a specific function. |
What is a perpetual motion machine? | A perpetual motion machine is a machine that can run forever, however scientists have never invented one that is successful. |
What are two examples of a pulley? | A elevator, a well, and a flagpole. |
What are two examples of a wheel and axle? | A door knob, a hose tap, and a bike. |
What are two examples of a inclined plane? | A wheelchair ramp, a slide, and stairs. |
What are examples of a class 1 lever? | A seesaw, a pair of scissors, and pliers. |
What are examples of a class 2 lever? | A wheelbarrow, and a nutcracker. |
What are examples of a class 3 lever? | A stapler, tweezers, a broom, and a hockey stick. |
What are examples of a wedge? | A shovel, a knife, and a axe. |
What are examples of a screw? | A bottle cap, light bulb, and a screw driver. |
What is a machine? | A machine is a mechanical system that reduces the force required to accomplish work. |
What is the input force? | The force that is applied to the machine. |
What is the output force? | The force that the machine applies to the object. |
What is the mechanical advantage? | The amount by which a machine can multiply an input force. |
What is the ideal mechanical advantage? | The mechanical advantage of a machine that has no friction. |
What is the useful output work? | The work a machine is designed to perform. |
What is the input? | The effort. |
What is the output? | The load. |
What is a fulcrum? | The point that does not move. |
What is efficiency? | The efficiency of a machine is measures in useful work done by the machine compared to the work needed to operate it. |