STEM QUIZ

1. Sound

• Nature: Mechanical, longitudinal wave requiring a medium; cannot travel in a vacuum.
• Characteristics: Pitch (frequency), loudness (amplitude), timbre (quality), and speed (varies by medium/temperature).
• Reflection: Phenomena like echoes and reverberation.
• Ultrasound: Applications in cleaning, flaw detection, and medical imaging.
• Hearing range: 20 Hz to 20,000 Hz.

2. Work, energy, and power

• Work: Force causing displacement.
• Energy forms: Kinetic (motion) and potential (position/shape).
• Conservation: Energy is transformed, never created or destroyed.
• Power: Rate of doing work.

3. Gravitation

• Universal law: Every object attracts every other object.
• Gravity concepts: Free fall, acceleration due to gravity, mass (constant) vs. weight (variable).
• Fluids: Thrust, pressure, buoyancy, and Archimedes’ principle.

4. Force and laws of motion

• First law: Inertia (object stays at rest/motion unless acted upon).
• Second law: F = ma (Rate of change of momentum).
• Third law: Action and reaction are equal and opposite.
• Conservation of momentum: Total momentum in an isolated system remains constant.

5. Motion           

• Parameters: Distance vs. displacement, speed vs. velocity, acceleration.
• Types: Uniform, non-uniform, and uniform circular motion.
• Analysis: Distance-time and velocity-time graphs.
• Equations: Relationships between velocity, acceleration, time, and distance.