Simple Machines 1
What is a lever and how many classes of levers are there?
A lever is a rigid bar that rotates around a fixed point called a fulcrum. There are 3 classes of levers.
What is a pulley?
A grooved wheel with a rope, chain, or cable wrapped around it
What is a wheel and axle?
Two circular objects that are fastened together and rotate around a common axis
How many types of simple machines are there?
6
What are the three main parts of a lever?
The three main parts are the fulcrum, effort, and load.
Explain the difference between a fixed pulley and a movable pulley.
A fixed pulley stays in one place and changes the direction of the force, while a movable pulley moves with the load and reduces the effort needed.
Give an example of a wheel and axle used in daily life.
Examples include a doorknob, steering wheel, or rolling cart.
**Other answers may apply - teacher discretion.
What is a simple machine?
A device that has few or no moving parts and makes work easier for people to do; Performs a simple function (task).
What is a fulcrum?
A point at which a lever pivots.
Describe a situation where pulleys are commonly used in everyday life.
Pulleys are commonly used in flagpoles, elevators, and construction cranes.
**Other answers may apply - teacher discretion.
Identify the wheel and identify the axle in a rolling pin (what you roll out dough with).
What is a compound machine?
Made of 2 or more simple machines, usually made of moving parts, and performs more complex functions.
Identify which class of lever a seesaw belongs to and explain why.
A seesaw is an example of a first-class lever. It works by having the fulcrum in the center, with the load on one side and the effort on the other.
What is a compound pulley and an example of a compound pulley?
Uses a fixed and movable pulley; the amount of effort is less than half of the load. An example would be construction cranes.
Identify the simple machine: Pizza Cutter.
Wheel and axle.
What do we call it when the amount of force required from us becomes less?
Mechanical Advantage
Identify which class of levers a wheelbarrow is and explain why.
A wheelbarrow is a second class lever because the load is located between the fulcrum and the effort.
How does adding more pulleys to a system affect the amount of effort required to lift a load?
Adding more pulleys reduces the effort required to lift a load by distributing the weight over multiple ropes.
Why does a larger wheel compared to the axle increase the mechanical advantage?
A larger wheel increases the mechanical advantage because it allows the effort to be applied over a greater distance, reducing the force needed.
What is an example of a compound machine and what simple machines is it made up of?
A shovel is both a wedge and a lever.
**Other answers may apply - teacher discretion.