Physics Measurement and Vectors Quiz

Physical Quantities and Measurement Techniques

• Measurement tools include rulers and measuring cylinders for length and volume.
• Digital timers and clocks measure time intervals.
• Average value calculation: sum of all values divided by the number of values.
• Period of oscillation = time taken / number of swings.
• Scalars have magnitude only (e.g., speed, time, mass, energy, temperature).
• Vectors have both magnitude and direction (e.g., velocity, force, weight, acceleration, momentum).

Vectors

• Velocity is a vector because it includes speed and direction.
• Resultant force of two vectors at right angles can be calculated using the Pythagorean theorem.

Mass and Weight

• Mass is the amount of matter in an object.
• Weight is the gravitational force on an object with mass.
• Weight = mass × gravitational field strength (w = mg).
• Gravitational field strength is force per unit mass (equivalent to acceleration of free fall).
• Mass and weight can be compared using a balance.

Density

• Density is mass per unit volume (p = m/v).
• How to determine density in regular solids: measure its length, width, height, calculate volume, find the mass, and perform p=m/v calculation.
• For irregular solids : place the object into a measuring cylinder partially filled with water, record the increase in water level to determine volume, find mass via a balance - then perform p=m/v calculation.

Motion

• Speed is distance travelled per unit time.
• Velocity is speed in a specific direction.
• Average speed = total distance travelled / total time taken.
• Acceleration is change in velocity per unit time (a = Δv/Δt).
• A steeper line on a distance-time graph indicates higher speed.
• A falling object without air resistance accelerates at constant rate, its speed increases steadily.
• Air resistance increases with speed of a falling object, eventually balancing the weight.
• Terminal velocity is the constant speed reached by a falling object when air resistance equals weight.

Forces

• Forces can change an object's size and shape.
• Spring constant is force per unit extension.
• Limit of proportionality: force-extension relationship is linear until the limit of proportionality is reached.
• Resultant force of forces in a straight line is the sum of the forces (add them algebraically).
• Newton's Second Law :Force = mass × acceleration.
• Motion in circular path is due to a perpendicular force.
• Momentum = mass × velocity.

Turning Effects of Forces

• Moment of a force is the turning effect, Moment = force × perpendicular distance from the pivot.
• Principle of moments: total clockwise moment =total anticlockwise moment for a balanced body.
• Equilibrium:no resultant force, no resultant moment.

Momentum

• Impulse is the change in momentum, and is force × time interval
• Momentum is a vector .
• The principle of conservation of momentum states that the total momentum of a system remains constant if no external forces act.

Energy

• Energy can be kinetic, gravitational potential, chemical, elastic, nuclear, electrostatic or internal (thermal).
• Energy transfers occur during events, by forces, electricity, heating, waves.
• Energy cannot be created or destroyed; only transferred from one form to another, or to different locations.
• Sankey diagrams display energy transfers.

Energy Resources

• Various sources like fossil fuels, water (tidal, waves), geothermal, nuclear fuel, solar, wind.
• Some sources are renewable; others are not.
• Efficiency is a measure of how much of the input energy is converted into useful energy output.
• Power is energy transferred per unit time.

Pressure

• Pressure = force/area; pressure in liquid is the weight per unit area at a depth, P = p g h
• Pressure in real life scenarios include standing on a floor, pushing a door, etc.
• Pressure unit is Pascals (Pa).

Test your knowledge on physical quantities and measurement techniques, including the use of measurement tools and understanding the difference between mass and weight. This quiz also covers vector concepts such as velocity and resultant force calculations.