Physics Unit 2

the motion of a body is described using graphs.

a distance time graph shows the distance of a body from a starting point against time taken.

the steeper the line on a distance time graph, the greater the speed it represents.

Speen(m/s) = distance travelled(m) over time taken(secs)

The slope on the graph represents speed.

the steeper the slope, the greater the speed.

Velocity is speed in a given direction. if the body changes direction it changes velocity even if the speed is the same.

if the velocity of a body changes we can say that it accelerates. we can calculate acceleration using:

acceleration = change in velocity

                         time taken for the change

aceeleration = m/s(squared)

velocity = m/s

speed = m/s

the slope of a line on a velocity - time graph represents acceleration.

the area under the line on a velocity - time graph represents the distance travelled.

if the slope is negative the body is decelerating.

the bigger the area, the greater the distance travelled.

the slope of the line on a distance - time graph represents speed.

the sloope of the line on a velocity- time graph represents accelereation.

the area under the line on a velocity - time graph represents the distance travelled.