Work and Power
Power
A flagpole is an example of this simple machine
What is a Pulley
the point on a lever where the bar pivots around
the fulcrum
A device that changes a force
Machine
A simple machine that consists of two disks or cylinders, each with a different radius
Wheel and axle
The SI unit of power
Watt
An ax is used to chop wood what simple machine is it
What is a wedge
If a fulcrum is moved closer to the load what happens to the effort or force needed to lift that load
What is decreases or is less
Your school is building a new playground. Workers need to move a heavy wooden beam (about the weight of three adult men) from ground level up to the top of a 6-foot-tall structure where it will become part of the climbing frame.
The Challenge: Which simple machine would be most practical and safe to use? Why?
Incline Plane or Pulley
A v-shaped object whose sides are two inclined planes sloped towards each other
The SI unit of work
Joule
What kind of simple machines are used in scissors
wedge and lever
What class lever has the fulcrum on one end and the load at another end and the effort in the center
3rd Class lever
A community garden has an old, rusty metal gate that's difficult to open and close. It weighs about 50 pounds and needs to swing smoothly on its hinges without requiring excessive force from volunteers of varying ages and abilities
The gate currently requires a lot of force to move. What simple machine could be added or modified to make it easier to operate? Consider what's already present.
Lever
A rigid bar that is free to move around a fixed point
Lever
What is the work done by a lever that applies a 2N force over 5M?
10J
A ramp is an example of what simple machine and what could you do to the ramp to make it even easier or use even less effort
What is an incline plane and increase the distance
What class lever has the load in the center and the effort and fulcrum on opposite ends
What is a 2nd class lever
The Water Well Project
A rural community needs to draw water from a deep well (30 feet down) multiple times daily. They want a system that:
Pulley and Wheel and axle
Pulley
arah lifts a 30-pound box from the ground to a shelf that is 4 feet high. It takes her 6 seconds to complete the lift.
Part A: Calculate the work done on the box. (Hint: Work = Force × Distance)
Part B: Calculate the power used to lift the box. (Hint: Power = Work ÷ Time)
120J and 20W
What simple machines are in a can opener
What are lever, screw and wedge
If a lever lifts a load of 1200 N and the effort was 600N what is the mechanical advantage of the lever
2
A bookstore receives a delivery of 200 heavy boxes of books. The store has three floors, and the loading dock is on the ground level. The elevator is broken. They need to move boxes efficiently to all three floors in 4 hours with a team of 5 people.
The Challenge:
Incline Plane and Pulley
An inclined plane wrapped around a cylinder
Screw