motion

• distance: d (symbol), metre (unit)
• time: t (symbol), seconds (unit)
• speed: v (symbol), m/s (unit)
• velocity: v (symbol), m/s (unit)
• acceleration due to gravity: g (symbol), m/s/s (unit)
• mass: m (symbol), kilogram (unit)
• weight: Fg (symbol), newtons (unit)
• how do you convert km/h to m/s?

  by dividing by 3.6
• how do you convert kilograms into metres?

  by multiplying by 1,000
• how do you convert metres into centimetres?

  by multiplying it by 100
• how do you convert m/s into km/h?

  by multiplying by 3.6
• forces cause things to change shape, direction, and speed, but they are invisible; we can only see and measure their effects on motion
• kinematics is the pure description of motion and is the starting point to understand why objects move the way they do
• speed is calculated as distance travelled divided by time taken
• speed is typically measured in standard units like meters and seconds; to convert m/s to km/h, multiply by 3.6
• average speed is the average of the instantaneous speeds over a specific time period
• distance: total amount of ground travelled
• distance is measured in meters and has no direction
• displacement: distance traveled in a stated direction and is the total change of position from a starting to a finishing point
• displacement has direction and is expressed as compass points, up or down, + or - and left or right
• all measurements can be categorised as either vectors or scalars
• scalars have magnitude
• vectors have magnitude and direction
• distance is a scalar value
• displacement is a vector value
• scalars have size but no direction
• vectors have size and direction
• si units = international standard of units
• si units include metre for distance, kilograms for mass, seconds for time and ampere for electric current
• Δ = change in value or difference
• positive acceleration = speeding up
• negative acceleration = slowing down
• 3 ways to accelerate: speeding up, slowing down and change in direction
• what is the equation for acceleration?

  a = Δv/t
• the units for acceleration is metres per second per second (m/s/s). it can also be written as metres per second squared (m/s² or ms-²)
• objects that are speeding up have positive acceleration, while objects that are slowing down have negative acceleration
• negative acceleration is sometimes referred to as deceleration
• velocity is a vector quantity
• acceleration is change in velocity therefore acceleration is a vector quantity too - it has direction
• in the scientific sense, an object accelerates whenever it slows down, speeds up or changes direction.