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Questions and Answers
What is the SI unit of energy?
What is the SI unit of energy?
Which of the following statements about kinetic energy is true?
Which of the following statements about kinetic energy is true?
How does power relate to force and velocity?
How does power relate to force and velocity?
What is the relationship between work output and energy input in terms of efficiency?
What is the relationship between work output and energy input in terms of efficiency?
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Which type of friction involves overcoming initial resistance until breakaway occurs?
Which type of friction involves overcoming initial resistance until breakaway occurs?
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What is potential energy primarily associated with?
What is potential energy primarily associated with?
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What happens to the molecules of a liquid when heat energy is continually added?
What happens to the molecules of a liquid when heat energy is continually added?
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Which of the following is true about the efficiency of machinery?
Which of the following is true about the efficiency of machinery?
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What is the state called when the resultant of all forces acting on an object is zero?
What is the state called when the resultant of all forces acting on an object is zero?
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What does momentum depend on?
What does momentum depend on?
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In a third-class lever, where is the effort located in relation to the load and fulcrum?
In a third-class lever, where is the effort located in relation to the load and fulcrum?
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How is Mechanical Advantage (MA) calculated?
How is Mechanical Advantage (MA) calculated?
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If a pulley system has a Mechanical Advantage of 4, what is the Velocity Ratio?
If a pulley system has a Mechanical Advantage of 4, what is the Velocity Ratio?
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What is a 'couple' in mechanical terms?
What is a 'couple' in mechanical terms?
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In a second-class lever, what is the relationship between load and effort?
In a second-class lever, what is the relationship between load and effort?
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Which of the following is an example of a first-class lever?
Which of the following is an example of a first-class lever?
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What is another term for negative acceleration?
What is another term for negative acceleration?
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According to Newton's First Law, what happens to a body at rest?
According to Newton's First Law, what happens to a body at rest?
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What does the formula $F = ma$ represent?
What does the formula $F = ma$ represent?
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In the context of circular motion, what would happen if centrifugal force is not applied?
In the context of circular motion, what would happen if centrifugal force is not applied?
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How is average velocity calculated?
How is average velocity calculated?
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What type of motion is characterized by repeated cycles over time?
What type of motion is characterized by repeated cycles over time?
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What determines the frequency of a simple harmonic oscillator?
What determines the frequency of a simple harmonic oscillator?
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What is the role of a linear restoring force in simple harmonic motion?
What is the role of a linear restoring force in simple harmonic motion?
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Study Notes
Matter
- Matter occupies space and has mass, existing in solid, liquid, or gaseous states.
- Matter is composed of small particles called atoms.
- Atoms are made up of protons, neutrons, and electrons.
- Four fundamental forces within atoms: gravity, the weak nuclear force, the electromagnetic force, and the strong nuclear force.
- All atoms follow the rule: Maximum number of electrons per shell = 2n², where n = shell number.
- Pure copper is an element composed of only copper atoms.
- Ions are atoms that have lost or gained electrons, becoming positive or negative.
- Isotopes are atoms of the same element with different numbers of neutrons. Their atomic number remains the same but atomic mass changes.
Compounds
- Compounds are substances formed by chemically combining one or more elements.
- Atoms bond together to form compounds, sharing electrons to form molecules.
- A compound is matter formed by chemically bonding two or more chemical elements.
Mixtures
- A mixture is composed of two or more substances retaining their individual characteristics.
- No chemical combination occurs as in compounds.
States of Matter
- All atoms and molecules vibrate constantly.
- Internal kinetic energy (heat) determines the state (solid, liquid, or gas).
- Elements, compounds, and mixtures exist as solids, liquids, or gases. The physical state of a compound has no effect on its chemical structure.
Solids
- Solids have definite volume and shape, independent of their container.
- Molecules in solids have very little energy; they vibrate in fixed positions.
- Solids are usually hard and strong. Metals are usually malleable and ductile.
Liquids
- Liquids have definite volume but no definite shape, taking the shape of their container.
- Molecules in liquids can move past one another but are still close together, and are partially bonded, causing surface tension.
Gases
- Gases have no definite volume or shape, filling their container.
- Molecules in gases move freely. Due to high molecular movement, gases are compressible.
Statics
- A force causes change in a body's motion (start, stop, accelerate, decelerate).
- Work can be done if energy is available.
- Equilibrium is a state where resultant forces on an object are zero, and the object's motion does not change.
- Mechanical advantage (MA) = Load/Effort.
Levers
- A lever is a simple machine used to reduce the force required to lift a load.
- A fulcrum is the pivot point of a lever.
- First-class lever: Fulcrum between load and effort (e.g., crowbar).
- Second-class lever: Load between fulcrum and effort (e.g., wheelbarrow).
- Third-class lever: Effort between fulcrum and load (e.g., human arm).
Velocity Ratio
- Velocity Ratio (VR) is the ratio of two speeds.
- In a pulley system, the rope's speed is 4 times the load's speed with an MA of 4.
- Velocity ratio (VR) = Distance Ratio = MA
Couples
- A couple consists of two equal and parallel forces acting in opposite directions on a body.
Centre of Gravity
- The Centre of Gravity (CG) of a body is the point where the entire weight of the body appears to act.
- For regular shapes, CG is the geometric centre.
- Irregular shapes the CG is where an object balances.
Stress, Strain, and Elasticity
- Stress is force per unit area, causing deformation.
- Strain is the deformation of a material due to stress.
- Below the elastic limit, strain is proportional to stress (Hooke's Law).
Shear Stress
- External forces tend to cause adjacent layers to slide.
- Shear stress tries to slice a body apart.
Torsional Stress
- A twisting force applied to a rod will slide sections of material over each other creating torsional stress.
Residual Stress
- Internal stress caused by abrupt/uneven temperature changes in materials.
Pressure and Buoyancy
- Pressure = Force/Area.
- Liquids are incompressible, and gases are compressible.
- Buoyancy: Displaced volume of fluid = weight of object.
- Lower density objects float on higher density objects.
Pascal's Law
- When pressure is applied to a confined liquid, the pressure is transmitted equally in all directions.
- Pascal's Law can be used practically in hydraulic jacks or brakes reducing the force needed to lift a load or put on the brake.
Properties of Solids, Liquids, and Gases
- Solids have definite shape and volume.
- Liquids have definite volume but no definite shape.
- Gases have no definite shape or volume.
Kinetics
- Kinetics focuses on the bodies state of motion.
- Displacement: Position relative to the origin.
- Speed: Distance/time.
- Velocity: Displacement/time, in a given direction.
- Acceleration: Change in velocity/time, direction change is also acceleration.
Newton's Laws
- First Law: A body will remain at rest or continue its uniform motion in a straight line unless acted upon by an external unbalanced force (Inertia).
- Second Law: The acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass (F = ma).
- Third Law: For every action, there is an equal and opposite reaction.
Linear Motion
- Motion in a straight line.
- Average speed: Distance/time.
- Average velocity: Displacement/time.
- Acceleration: Change in velocity per unit time; is the rate of change of velocity.
Circular Motion
- An object moving in a circular path is continually changing direction, which means it is always accelerating.
- The force required to keep an object moving in a circle is called a centripetal force.
Orbits
- Centrifugal force is a force that pulls outwards; it balances out gravity for objects in orbit.
- Gravity creates the attraction of objects in motion to each other.
Periodic Motion
- Repetitive motion, e.g. pendulum or spring.
- Period (T): Time for one complete cycle, frequency (f= 1/T) is the number of cycles per second.
Resonance
- Resonance occurs when two objects have the same natural frequency and interact.
- One object's vibration can be transferred to the other, amplifying it.
Dynamics
- Study of forces and their effect on motion and use of energy.
Weight and Mass
- Mass is a measure of the amount of matter in an object.
- Weight is the force of gravity acting on an object's mass. They are different but related.
Work
- Work is done when a force causes a displacement.
- Work = Force x Distance
Power
- Power is the rate at which work is done.
- Power = Work/Time
Energy
- Energy is the capacity to do work.
Potential Energy
- Stored energy due to position, condition, or chemical composition.
Kinetic Energy
- Energy due to motion.
Friction
- Resistance to sliding motion or rolling from contact between surfaces.
Heat
- Heat is energy transferred from high to low temperature areas.
Efficiency
- Ratio of work output to work input.
Momentum
- Momentum = Mass x Velocity (linear momentum); measures tendency of a body to remain in motion.
- Angular momentum = measures tendency of a rotating body to spin.
Impulse
- Impulse = Change in momentum
- Applying a force for a period of time (a "burn") changes momentum.
Fluid Dynamics
- Study of fluids in motion or at rest.
- Liquids are difficult to compress. While gases are compressible.
- Viscosity: Resistance to flow.
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Description
This quiz explores the fundamental concepts of matter, including its properties, atomic structure, and the distinctions between compounds and mixtures. Test your understanding of atoms, ions, isotopes, and the forces at play within them. Dive deep into the world of chemistry and solidify your knowledge of these essential concepts.
