Exploring Linear and Angular Quantities and Ergonomic Design.pptx
- 1. Exploring Linear and Angular Quantities & Ergonomic Design Understanding how objects move and interact with humans is essential for creating better designs. Let's explore these fascinating relationships through simple activities and real-world examples. by ANGELIQUE TOLENTINO DEL ROSARIO
- 2. Motion in Our World Movement surrounds us in countless forms. We experience both straight-line movements and rotational motions daily. Linear motion Movement along a straight path, like walking forward or a car driving down a road. Angular motion Rotation around a point or axis, like a spinning wheel or opening a door.
- 3. What Are Linear and Angular Quantities? Linear Quantities • Position (s): location in space • Velocity (v): rate of position change • Acceleration (a): rate of velocity change Angular Quantities • Angle (θ): rotational position • Angular velocity (ω): rate of rotation • Angular acceleration (α): rotation rate change
- 4. Visualization: Spinning and Sliding We can observe both types of motion in common activities: • Pushing a rolling ball demonstrates linear motion - distance moved straight ahead • Spinning a top shows angular motion - rotation around a central axis These simple examples help us visualize how objects move through space.
- 5. Activity: Measuring Arc Length with a String Materials needed: • String • Marker • Various circular objects • Ruler This hands-on activity demonstrates the relationship between arc length (s) and angle (θ). Where θ is measured in radians and r is the radius.
- 6. Activity: Whirl and Walk Setup Attach a string to a small toy or weight. Mark a straight path on the ground. Angular Motion Whirl the toy in a circle above your head. Note the constant radius and angular speed. Linear Motion Walk along the straight path at a steady pace. Compare this to the whirling motion. Compare Walking speed (v) vs. whirling speed (ω·r). Both cover distance but in different ways.
- 7. Hands-On: The Bike Wheel Demo Instructions: 1. Hold a bicycle wheel by its axle 2. Spin the wheel at different speeds 3. Observe how points at different distances from center move This demonstrates how linear velocity relates to angular velocity and radius.
- 8. Activity: Matching Rotations and Distance Mark and Roll Place a dot on the edge of a can. Roll it on a flat surface and measure how far it travels in one rotation. Measure Circumference Wrap string around the can to find its circumference. Compare to the distance rolled. Calculate Relationship For each complete rotation (2π radians), the can rolls exactly one circumference (2πr).
- 9. Connecting Linear and Angular Quantities (Summary) Key equations that connect these two types of motion: Arc length equation: Distance traveled along an arc Velocity relationship: Linear speed at radius r Acceleration relationship: Linear acceleration at radius r
- 10. Ergonomics: Linking Physics and Design What is Ergonomics? The science of designing products, systems, and processes to fit the people who use them. Good ergonomic design considers: • Human comfort and safety • Efficiency and usability • Physical capabilities and limitations Physics principles of motion directly influence how we create comfortable, safe designs.
- 11. Ergonomics in Building Design Door Handles Placed at average elbow height (1.05m). Leverage principles determine handle length and rotation force needed. Curved Staircases Riser/tread ratios follow the golden ratio. Inner and outer radius differences accommodate natural stride lengths. Emergency Exits Turn radii calculated for optimal flow during evacuations. Wider turns allow faster angular movement for crowds.
- 12. Vehicle Ergonomics and Safety Steering Wheels Diameter optimized for comfortable angular motion. Small rotation provides sufficient turning leverage. Dashboard Layout Controls positioned to minimize arm rotation and reach time. Critical controls require minimal angular displacement. Seats and Headrests Designed to support the body during both linear and angular acceleration, reducing whiplash and injury risk.
- 13. Ergonomic Furniture Design Office Chairs Feature adjustable height (linear) and tilt mechanism (angular). Pivot points align with body joints for natural movement. Desks Height and distance optimize arm angles and reach distances. Proper positioning reduces repetitive strain injuries. Rocking Chairs Rocker curve radius creates comfortable angular displacement. Center of gravity and momentum carefully balanced.
- 14. Toy Design: Physics Matters Physics principles make toys fun and safe: Spinning tops Gyroscopic stability through angular momentum Hula hoops Sustained angular motion through rhythmic force Toy cars Wheels convert rotation to linear movement Swings Pendulum motion with arc length (s = rθ) Well-designed toys naturally teach physics concepts through play.
- 15. Group Activity: Ergonomic Chair Challenge Measure Evaluate chairs for angular range (tilt) and linear adjustability (height, seat depth). Test Have team members sit and perform typical tasks. Note comfort issues and ergonomic problems. Analyze Apply physics principles to identify specific improvements needed for better comfort. Redesign Sketch improved chair design with better alignment of rotation points and adjustment ranges.
- 16. Group Activity: Invent a Toy with Physics Challenge Guidelines: 1. Work in teams of 3-4 students 2. Design a toy that uses both linear and angular motion 3. Consider safety, ergonomics and target age group 4. Sketch design and explain physical principles 5. Build simple prototype if materials available This activity connects physics understanding with creative design thinking and ergonomic principles.
- 17. Reflection: Real-World Examples Bicycle Mechanics Foot force creates angular motion of pedals and crank. Chain converts this to wheel rotation, producing linear forward motion. Lock Mechanisms Key rotation (angular) moves pins linearly to align and unlock. Combines both motion types for security and usability. Adjustable Lamps Multiple joints provide angular adjustment. Spring tensions balance gravitational forces at various positions.
- 18. Summary Table: Physics in Everyday Object Design Application Linear Angular Ergonomics Impact Chair Height Yes Yes Supports healthy posture Car Steering No Yes Reduces driver fatigue Toy Wheels Yes Yes Safe, smooth play Building Doors Yes Yes Easy, safe access Most well-designed objects thoughtfully integrate both types of motion for optimal human use.
- 19. Key Takeaways Connected Motion Types Linear and angular quantities have direct mathematical relationships in real-world movements. Physics-Based Design Ergonomic design applies physics principles to optimize human comfort, safety, and efficiency. Everyday Innovation Simple physics activities reveal the sophisticated design thinking behind ordinary objects we use daily.
- 20. Discussion and Q&A Reflection Questions: • How can you apply these physics concepts to improve objects you use daily? • Which activities helped you understand the connections most clearly? • What ergonomic problems have you noticed that could be solved with better physics application? • How might designing for different body types change the ergonomic calculations? Your insights and questions help deepen understanding of these important relationships between physics and design.