1. 2 Velocity and acceleration 04 January 2016 CarriagewaysCarsVans Local roads Single carriageway Dual carriageway Motorways towing a trailer Know your limit! What are the UK speed limits for cars and vans? Vans between 2000kg and 7500kg.

2. 2 Velocity and acceleration 04 January 2016 CarriagewaysCarsVans Local roadsAs marked Single carriageway roads6050 Dual carriageway roads7060 Motorways70 * towing a trailer* 60 Know your limit! Why do you think vans are lower unless they weigh under 2000kg?

3. 2 Velocity and acceleration What is the difference between speed and acceleration? What is acceleration and what are its units? What is deceleration? 04 January 2016 Motorways and dual carriageways have a central barrier and higher maximum speeds. Why is this safer than a single carriageway at 60mph?

4. World Records Usain Bolt is the 100m world record holder. Time = 9.58 seconds. What was his average speed for this distance? Speed = Why was this the average speed? What condition(s) would have to be met to make a valid record?

5. World Records Usain Bolt is the 100m world record holder. Time = 9.58 seconds. What was his average speed for this distance? Speed = distance = 100m = 10.44 m/s time9.58s Starts at zero and he takes time to reach his maximum speed. Wind speed Track distance Timing system

6. Velocity = speed in a given direction On a treadmill a speed is set. The belt runs at the speed set. E.g. 3 m/s How fast is the runner running (speed)? How quickly do they move in the direction they are running (velocity)? Velocity tells us how quickly we are travelling in the direction we want to go.

7. Direction Velocity tells us how quickly we are travelling in the direction we want to go. If we wanted to travel from Nottingham to Donington the A52 is the most direct route. Distance = 48 miles. Time = 1 hour. However, travelling due East is shorter: 40 miles. What is the speed for this journey? What is the velocity due East?

8. Direction Velocity tells us how quickly we are travelling in the direction we want to go. If we wanted to travel from Nottingham to Donington the A52 is the most direct route. Distance = 48 miles. Time = 1 hour. However, travelling due East is shorter: 40 miles. Average speed for this journey = 48 mph Velocity due East = 40 mph East!

9. Movement in a circle If an object moves in a circle at a constant speed of 10m/s what is its velocity? A B C D Speed (m/s) Velocity (m/s) A10 B C+10 D10 +

10. Movement in a circle A B C D Speed (m/s) Velocity (m/s) A10-10 B100 C +10 D100 +

11. Acceleration = Change in velocity per second Acceleration = change in velocity (m/s) (m/s 2 )Time taken (s) E.g. Rita Queen of speed accelerates from 0 to 30 m/s in 3 seconds. What is its acceleration in m/s 2 ? How can an object accelerate if its speed is constant?

12. Summary Velocity is speed in a given direction. Acceleration is the change of velocity per second. An object travelling at a constant speed is accelerating if its direction is changing.

13. Velocity = speed in a given direction On a trip across the Atlantic a plane takes 1 hour longer going west than going east. The air speed is the same for both trips. Why the difference? New YorkLondon 7 hours 8 hours

14. Velocity = speed in a given direction New YorkLondon 7 hours 8 hours Air speed 540mph Wind 60mph Velocity = 600mph Wind 60mph Velocity = 480mph