Starter Directions: Match the units on the right with the correct measurement on the left. 1. F = __________________ 125 kilograms 2. m = _________________23 kgm/s 3. a = __________________3 m/s2 4. v = __________________29 meters/sec 5. d = _________________228 meters 6. p = __________________6 newtons

Mechanical Advantage Day 26

Essential Question  Why use simple machines?

Simple Machines  /simplemachines/sm1.html /simplemachines/sm1.html

Explain: Mechanical Advantage Directions:Complete the two steps. 1. Write the definition for Mechanical Advantage 2. Create a T-chart for Mechanical Advantage for Force and Mechanical Advantage for Distance using the notes provided on simple machines and mechanical advantage. T-chart should include: – Formula for MA=Force and MA=Distance – Definitions for output force, input force, distance effort, and distance resistance. – Give one example of MA=force and MA=distance

Teacher Explain Input/Output Force

Explain: Mechanical Advantage Mechanical Advantage can also be calculated by counting the number of ropes in a pulley. Directions: What is the MA in each pulley?

Explain: MA of Force Directions: Where is the input force and output force located? A. B.

Simple Machines and Mechanical Advantage Direction: Label as Input force or Output Force. 1. You lift a 200N object. 2. A wedge applies 400N of force to a piece of wood. 3. You push 240N on a lever. 4. You turn a screw with 30N of force. 5. A pulley applies 48N of force up.

Explain: MA of Distance Directions: Where is the distance effort and distance resistance?

Simple Machines and Mechanical Advantage Direction: Label as distance effort or distance resistance. 1. You use an incline plane to lift a car up 4 meters. 2. You use a 10 meter ramp to raise up a car. 3. You lift a 200kg object up 2meters. 4. The distance you push down on a lever. 5. The distance the object moves with a lever.

Explain: MA  Direction: What is the distance mechanical advantage of the following diagram? Make sure to show the formula and show how you got the answer.

 Direction: What is the force mechanical advantage of the following diagram? Make sure to show the formula and show how you got the answer.

The mechanical advantage of a lever is the ratio of the length of the lever on the applied force (effort force - EF) side of the fulcrum to the length of the lever on the resistance force (RF) side of the fulcrum. Lever

Inclined Plane - Mechanical Advantage  The mechanical advantage of an inclined plane is equal to the length of the slope divided by the height of the inclined plane.

Wedge – Mechanical Advantage  The mechanical advantage of a wedge can be found by dividing the length of either slope (S) by the thickness (T) of the big end. S  As an example, assume that the length of the slope is 10 inches and the thickness is 4 inches. The mechanical advantage is equal to 10/4 or 2 1/2. As with the inclined plane, the mechanical advantage gained by using a wedge requires a corresponding increase in distance. T

Wheel and Axle  MA= radius of wheel/radius of axle

Screw

Diagrams of Pulleys Fixed pulley: A fixed pulley changes the direction of a force; however, it does not create a mechanical advantage. Movable Pulley: The mechanical advantage of a moveable pulley is equal to the number of ropes that support the moveable pulley.

Explain: Efficiency Efficiency in science means… a.) Formula is output work/input work x 100% Wo x 100% Wi b.) amount of energy lost in a system Efficiency wants to be at 100% but NO machine has 100% efficiency you loose it to heat, friction, sound, etc.

Exit Slip: MA  Write the formulas for Mechanical Advantage