Week 3 Simple and Compound Machines

Simple Machines AND COMPOUND MACHINES Simple Machines What are Simple Machines? Simple machines can help us make work easier. They have a simple build and do not have many parts. Pulley How does the pulley help us? The pulley helps us by lifting a load from a low area to a high area. We use pulleys to help us lift a flag or raise up curtains. How does the pulley WORK? Combining two or more pulleys allows one to raise heavy objects off the ground using minimum effort. In this way, the mechanical advantage is increased. TYPES OF PULLEY 1. Fixed Pulley It is a simple pulley that is attached to a stationary object, such as a beam or ceiling. It does not move and only changes the direction of the applied force. While it does not provide any mechanical advantage in terms of force, it can be useful in changing the direction of the force or in allowing the user to exert force in a more convenient direction. TYPES OF PULLEY 2. Movable Pulley It is a pulley that moves along with the load being lifted or lowered. It is attached to the object being moved, and as such, it provides a mechanical advantage by reducing the amount of force required to move the load. When using a movable pulley, the force required to lift the load is half of the actual weight of the load, making it easier to handle heavier objects. TYPES OF PULLEY 3. Compound Pulley It is a combination of fixed and movable pulleys. It consists of multiple pulleys mounted on a single shaft or frame, and the rope or cable loops around each pulley in a series. This configuration allows for a greater mechanical advantage, making it possible to lift heavy loads with less force. Compound pulleys are commonly used in systems like cranes and elevators. TYPES OF PULLEY Wheel & Axle How does a Wheel & Axle help us? A wheel and axle helps us by making it easier to carry heavy loads quickly over long distances. They can also help us steer, turn and lift loads. A wheelchair helps people move their bodies from one place to another. How does a Wheel & Axle work? A rotational force or torque is applied to one part, which then rotates and transmits the force to the other part. Mechanical advantage is gained by increasing the size of the wheel. A wheel and axle has many functions, including transporting and lifting objects. Bicycles and cars are equipped with wheels and axles to roll over large distances. Besides, rolling over a surface generates less friction than sliding. Lever How does a lever help us? Levers helps us by making it easier to lift heavy objects. Seesaws are fun to use with friends and wheelbarrow help us carry loads over distances. How does a lever WORK? When a force is applied at a point on the beam, it rotates about the support point. The function of a lever is to multiply the applied force so that a heavy object can be raised. The applied force is called effort, the object is the load, and the support is the fulcrum or pivot. Types of LEVER 1. First Class The load is at one end of the beam, and the effort is at the other end. The fulcrum is between the load and effort. Depending upon the position of the fulcrum, the effort can be high or low. If the fulcrum is closer to the load than the effort, the effort is low. The effort is high if the fulcrum is closer to the effort than the load. Types of LEVER 2. Second Class The fulcrum is at one end of the beam, and the effort is at the other end. The load is located between the fulcrum and effort. The position of the load affects the effort. If the load is closer to the fulcrum than the effort, the effort is low. The effort is high if the load is closer to the effort than the fulcrum. Types of LEVER 3. Third Class The fulcrum is at one end of the beam, and the load is at the other end. The effort is located between the fulcrum and load. The effort depends upon its position. The effort is high if it is closer to the load than the fulcrum. The effort is high if it is closer to the fulcrum than the load. Wedge How do Wedges help us? Wedges help us by making it easier to split or cut an object. Objects like forks, knives and even our teeth are wedges. How do Wedges work? A wedge works by changing the direction of the applied force, enabling it to cut through materials. The difference between an inclined plane and a wedge is that a wedge moves, whereas an inclined plane remains still. Screw How do Screws help us? Screws help us by lifting things or keeping them together. A light bulb is screwed into the base, so it does not fall out and lights up! How do Screws work? One end of the screw forms the head, and the other end is sometimes pointed and forms the tip. A screw works on the principle of converting rotational motion into translational motion. When a rotational force or torque is applied to the head, the screw rotates and moves linearly. A screw consists of threads, and the distance between each thread is called the pitch. The mechanical advantage can be gained by increasing the pitch. A screw is used for holding things, drilling holes, and lifting objects. Inclined Plane How do inclined PLanes help us? Inclined plane helps us by pushing or rolling an object to a higher or lower area. A slide is a fun and safe way to go from a higher area to a flat area. How do inclined Planes work? An inclined plane is the simplest of all simple machines. It does not consist of any moving parts, neither does it move. An inclined plane consists of a slope that makes a fixed angle to the surface on which it rests. It moves an object from a lower level to a higher level without taking it vertically. In other words, the force applied to the object is less than its weight. A more extended inclined plane provides a higher mechanical advantage, and the object can be raised with less effort. WHAT SIMPLE MACHINE IS THIS? INCLINED PLANE WHAT SIMPLE MACHINE IS THIS? WEDGE WHAT SIMPLE MACHINE IS THIS? LEVER WHAT SIMPLE MACHINE IS THIS? WHEEL AND AXLE WHAT SIMPLE MACHINE IS THIS? SCREW WHAT SIMPLE MACHINE IS THIS? PULLEY Compound Machines What is/are the simple machine/s in this object? Wheel and axle  Pulley  Lever  Screw  COMPOUND MACHINES A compound machine is a combination of two or more simple machines that operate together. COMPOUND MACHINES Many familiar compound machines, such as a car, a washing machine, or a clock, are combinations of hundreds or thousands of simple machines. Compound Machine Corkscrew Inclined Plane Wedge Screw Lever Wheel and Axle Compound Machine Jack Inclined Wedge Screw Lever Plane A Wedge in a Compound Machine: Stapler  Staples are wedges. They cut through paper because their ends are pointed in a wedge shape.  Simple machines in a stapler:  Wedge  Lever A Wedge in a Compound Machine: Scissors The cutting edge of scissors is a wedge. Simple machines in a pair of scissors: Wedge Lever EFFICIENT SIMPLE AND COMPOUND MACHINES PULLEY WHEEL AND AXLE LEVER WEDGE SCREWS PULLEY Translational and Rotational Motion in Simple and Compound Machines Translational Motion in Machines • Translational motion is straightline movement from one point to another. • In machines, it's often the result or purpose of using force. In Simple Machine Machine Inclined Plane Lever Wedge Translational Example Motion The box moves in a Pushing a box up a straight line up the ramp ramp. The load moves Using a seesaw to upward/downward lift an object in a line. Driving a wedge The door moves under a door slightly upward. In Compound Machine Machine Wheelbarrow Scissors Car jack (screw + lever) Translational Motion Example The load is lifted and pushed forward. The blades move linearly to cut. The car rises upward in a straight line. Rotational Motion in Machines • Rotational motion is when a part of the machine spins or turns around an axis. In Simple Machines Machine Pulley Wheel and Axle Screw Rotational Motion Example The wheel rotates as the rope moves. Turning the axle spins the wheel. Turning the screw rotates it into material. In Compound Machines Machine Bicycle Egg beater Drill Rotational Motion Example Pedals and wheels rotate. The handle turns, rotating beaters. The motor rotates the drill bit. How does translational motion contribute to the functionality of simple and compound machines? In Simple Machines • Makes it easier to move, lift, or shift objects in a straight line. Machine Inclined Plane Wedge Lever How It Contributes to Type of Motion Functionality Allows objects to move Translational motion upward with less force over a distance. Converts force into a Translational motion straight-line splitting or lifting action. The load moves up/down in Translational at load a straight path when the end lever is used. In Compound Machines • Allows precise positioning or movement of parts in complex machines. Machine Part Involved Wheelbarrow Tray Scissors Blades Crane Hook Hook Translational Motion Function Moves load forward in a straight line. Blades move linearly to cut. Hook moves vertically up/down to lift loads. How does rotational motion contribute to the functionality of simple and compound machines? In Simple Machines • Helps to redirect force, reduce friction, and make lifting or turning easier. Machine Bicycle Electric Mixer Drill Rotational Motion Rotating Part Function Transfers pedal force Wheels, gears, pedals to wheel to create forward motion. Spins beaters to mix Beaters ingredients. Rotates to bore holes Drill bit into surfaces. In Compound Machines • Drives continuous motion, enables mechanical work like spinning, drilling, or moving. Machine Rotating Part Bicycle Wheels, gears, pedals Electric Mixer Beaters Drill Drill bit Rotational Motion Function Transfers pedal force to wheel to create forward motion. Spins beaters to mix ingredients. Rotates to bore holes into surfaces. PERFORMANCE TASK 2: Engineering Motion: Building Efficient Machines The learners will work in small groups (per group-builders, thinkers, and w7 members riters) to design, build, and test a working prototype of a simple or compound machine that demonstrates both translational and rotational motion. They will then explain the physics behind the motion of their machine and reflect on its efficiency. MATERIALS (Suggested) ● Cardboard, wood, strings, pulleys, rubber bands ● Screws, nails, glue, hot glue gun ● Plastic wheels, gears, syringes (for hydraulics) ● Rulers, protractors, stopwatch, weights (Students are encouraged to reuse/recycle materials as much as possible) REUIREMENTS: 1. Must include: - At least one rotating component (wheel, gear, pulley, etc.) - At least one translational component (sliding, pushing, lifting, etc.) - At least one simple machine (lever, pulley, etc.) 2. Must accomplish a useful task, such as: - Lifting a weight - Moving an object - Launching something 3. Use recycled or low-cost materials DELIVERABLES: 1. Prototype (presented in class or video demonstration) 2. Written Report (2–3 pages) with: - Description and labeled diagram of your machine - Explanation of how it works using physics terms - Calculations of force, torque, efficiency (if applicable) - Reflection on design process and teamwork DELIVERABLES: 3. Short Group Presentation (3–5 minutes): - Show the working prototype - Explain how translational and rotational motion are involved EXCELLENT 16 to 20 pts PROFICIENT 11 to 15 pts DEVELOPING 6 to 10 pts NEEDS IMPROVEMENT 1 to 5 pts