1. Acceleration Fast as fast can be you’ll never catch me!

2. Acceleration, What is it? Most people think this means getting faster, but it is more precisely defined. When a car is getting faster, how long it takes to increase its speed (or velocity) is important. A car with good acceleration increases its velocity in a short time. Many cars are judged in this way. e.g. The 2001 Honda Accord 3.0 V6 goes from 0- 60 mph in 7.8 seconds, whereas the Lotus Elise 111 does 0-60 mph in 5.8 seconds. -Taking two seconds less means the Lotus has better acceleration. Check out this little clip for a demonstration of change in speed in a very short period of time

3. Lets look a little further… Acceleration is defined as being: In the case of the Lotus (see previous page), its acceleration is:previous page Notice the odd unit for acceleration - it's a "velocity" per "time". What 10.3 mph/s means, of course, is that every second the car's velocity increases by 10.3 mph.

4. Lets expand this definition a little more… Normally in Physics we use metres per second (m/s) for speeds and velocities, and this gives us a very odd looking unit for acceleration. For example: A Tour de France cyclist accelerates from 10 m/s to 15 m/s in 10 s: Yes, that's right! Acceleration is normally measured in metres-per-second-per-second! All this means is a change in velocity per second. Sometimes you may see accelerations written as m/s² rather than m/s/s. They are the same thing. Notice that the change in velocity is given by: final velocity - initial velocity.

5. Now, try this question: A ball is dropped off the top of a building. It reaches 30 m/s after 3 seconds. What was its acceleration? a)90 m/s/s90 m/s/s b)10 m/s/s10 m/s/s c)27 m/s/s27 m/s/s What do you think?

6. A ball is dropped off the top of a building. It reaches 30 m/s after 3 seconds. What was its acceleration? Make sure you show your work, as you can pick up marks - especially if you include the correct units!

7. If I was walking at 1 m/s and increased up to a sprint of 7 m/s in 3 seconds. What was my acceleration? a) 2.7 m/s/s2.7 m/s/s b) 10 m/s/s10 m/s/s c) 2 m/s/s2 m/s/s

8. There is one special note: If the answer is a positive number, there is an increase in speed. If the answer is a negative number there is a decrease in speed. See below: A driver brakes hard, and slows from 25 m/s to 5 m/s in 5 seconds. What was the vehicle's acceleration? In other words, it slows down by 4 m/s every second. Or its deceleration is 4 m/s/s.