Physics

• The SI unit of energy is the joule (J).
• ruler - used to measure small distances of a few centimeter
• trundle wheel - used to measure large distances
• tape measure - distances of a few metres
• measuring cylinders- volume of liquids
• mass - kg
• length - metres
• time- second
• distance - metres
• stop clock - time interval between two events
• weight = force due to gravity acting on an object
• mass is the amount of matter in an object, measured in kilograms (kg).
• A toy car rolls down a ramp and hits a cushion
• Constant velocity


  Velocity that does not change
• Where on the speed-time graph is the velocity constant


  The horizontal part of the line
• Distance travelled


  Represented by the area under the graph line
• Average velocity


  Calculated as distance divided by time
• A bus travels along a straight road
• To find the velocity of the bus after 25 seconds

  Read the value from the graph at 25 seconds, which is 6 meters per second
• To find how long the bus was stationary


  Look for the parts of the graph where the velocity is zero
• The answer for how long the bus was stationary is the time period where the velocity is zero
• Distance


  Area under the graph line
• Average velocity


  Distance divided by time
• A bus travels along a straight road, the graph shows how the velocity of the bus changes during a short journey
• Distance is given by the area under the curve, acceleration is given by the gradient
• Velocity of the bus after 25 seconds


  6 meters per second
• Bus stationary during its journey

  10 seconds
• Equation linking acceleration, change in velocity and time taken


  Acceleration = change in velocity / time taken
• Unit of acceleration


  Meters per second squared
• Equation linking average speed, distance moved and time taken


  Average speed = distance moved / time taken
• The bus travels further in the first 30 seconds of its journey than it does during the last 30 seconds
• Initial length of the queue

  6.1 meters
• Explaining how to use the graph to work out the number of times person x is stationary


  The flat portions of the graph indicate when the person is stationary, there are 7 such flat portions
• Weight


  Force given in Newtons
• Mass


  Quantity given in Kilograms
• Mass is unchanged regardless of location, weight depends on gravitational field strength
• Equation linking weight, mass and gravitational field strength


  Weight = Mass x Gravitational field strength
• Density


  How close together particles are, heavy objects have high density
• Equation for density


  Density = Mass / Volume
• Measuring density of symmetrical objects


  • Measure mass, measure dimensions to calculate volume, then use density equation