Mechanics Quiz: Scalars and Vectors

Mechanics

• Scalars are quantities that only have magnitude (e.g., speed, distance, mass).
• Vectors are quantities that have both magnitude and direction (e.g., velocity, displacement, force).
• Distance is the total path length covered by an object.
• Displacement is the straight-line distance between the starting and ending points of an object's motion.
• Speed is the rate of change of distance.
• Velocity is the rate of change of displacement.
• Acceleration is the rate of change of velocity.
• Equations of motion relate displacement, time, speed, velocity, and acceleration for uniformly accelerated motion. The core equations include:
  • v = u + at
  • s = ut + 1/2at²
  • v² = u² + 2as
  • s = (v+u)/2 * t
• Forces cause objects to accelerate. Force is measured in Newtons (N).
• Newton's first law of motion states that an object will remain at rest or in uniform motion in a straight line unless acted upon by a resultant force.
• Newton's second law of motion states that the acceleration of an object is directly proportional to the resultant force acting on it and inversely proportional to its mass. (F = ma)
• Newton's third law of motion states that for every action, there is an equal and opposite reaction.
• Weight is the force of gravity acting on an object. Weight = mass × gravitational field strength (w = mg).
• Momentum is the product of an object's mass and velocity (p = mv).
• Conservation of momentum states that the total momentum of a system remains constant if no external forces act on it.

Thermal Physics

• Temperature is a measure of the average kinetic energy of the particles in a substance.
• Heat is the energy transferred from one object to another because of a difference in temperature.
• Specific heat capacity of a substance is the amount of heat needed to raise the temperature of 1 kg of the substance by 1°C.
• Latent heat is the energy required to change the state of a substance without changing its temperature. Latent heat of fusion is for melting or freezing, and latent heat of vaporization is for boiling or condensing.
• Conduction, convection, and radiation are three methods of heat transfer.
• Conduction involves the transfer of heat through a material by the particles vibrating and colliding.
• Convection involves the transfer of heat through a fluid (liquid or gas) by the movement of the fluid itself.
• Radiation is the transfer of heat through electromagnetic waves.

Waves

• Waves transfer energy without transferring matter.
• Transverse waves have oscillations perpendicular to the direction of energy transfer.
• Longitudinal waves have oscillations parallel to the direction of energy transfer.
• Wave properties include:
  • Amplitude: height of the wave.
  • Wavelength: distance between two corresponding points on a wave.
  • Frequency: number of waves passing a point per unit time.
  • Period: time taken for one complete wave to pass a point.
  • Speed: how fast the wave travels. (speed = frequency × wavelength)
• Reflection, refraction, and diffraction are wave phenomena.
• Reflection occurs when a wave bounces off a surface.
• Refraction occurs when a wave changes speed and direction as it passes from one medium to another.
• Diffraction occurs when a wave spreads out as it passes through an opening or around an obstacle.

Electricity

• Current is the rate of flow of charge. ( I = Q/t).
• Potential difference (voltage) is the energy transferred per unit charge. (V = W/Q).
• Resistance opposes the flow of current. (V = IR).
• Series circuits have components connected in a single loop.
• Parallel circuits have components connected across multiple branches.
• Electrical power is the rate at which electrical energy is transferred. (P = IV)
• Circuits use components such as resistors, capacitors, and diodes to create a path for current flow.

Light

• Reflection of light occurs when light bounces off a surface.
• Refraction of light occurs when light changes speed and direction as it passes from one medium to another.
• Laws of reflection state that the angle of incidence equals the angle of reflection.

Atomic Structure

• Atoms are composed of protons, neutrons, and electrons.
• Protons have a positive charge.
• Neutrons have no charge.
• Electrons have a negative charge.
• Atomic number represents the number of protons in an atom.
• Mass number represents the total number of protons and neutrons in an atom.