Speed and Distance time graphs
Speed is a measure of how fast something will move in a certain amount of time. The formula for speed is
speed(m/s)= distance travelled(m) / time taken(s)
On a distance time graph- time is on the horizontal axis and distance is on the vertical axis.
A diagonal line going up represents steady speed. A horizontal line represents stationary. A diagonal line going going down represents a steady speed returning to the start.
The steeper the line on a distance-time graph, the greater the speed it represents.
1. Always show the stages in your working when you do calculations. Always include a unit with your answer is one is not given.
2. Make sure that you always label the axes on a graph with a quantity and a unit.
Velocity and acceleration
On a velocity-time graph the time is on the horizontal axis, velocity is on the vertical axis. Velocity is speed in a given direction.Acceleration is change of velocity per second. If the velocity of a body changes, we say that it accelerates.
acceleration(m/s²) = change in velocity(m/s) / time taken(s)
Example: A car accelerates in 5s from 25m/s to 35m/s. Its velocity changes by 35-25=10m/s. So its acceleration is 10/5=2 m/s²
A diagonal line going up represents constant acceleration. A horizontal line represents constant velocity. A diagonal line going down represents constant acceleration. The steeper the slope, the greater the acceleration.