Movement and Position Flashcards
How do you work out speed?
speed = distance / time m/s = m / s
How do you work out acceleration?
acceleration = change in velocity / time
a = (v-u) / t
m/s squared
What does the gradient of a distance time graph show?
speed
What does the gradient of a velocity time graph show?
acceleration
How do you work out the gradient on a graph?
change in y / change in x
What happens to your acceleration when you travel down a steeper slope?
your acceleration is faster by still constant
What is velocity?
speed in a particular direction (vector)
What is acceleration in the equation?
your average acceleration as the actual acceleration may vary during the time over which the acceleration is recorded
What is your speed in the equation?
your average speed because your actual speed may vary if the time over which the journey is recorded is substantial
How do you work out velocity?
velocity = distance / time m/s = m / s
Describe an experiment to investigate the motion of an everyday object
- Hold a car just before the first light gate
- Mark a line on the ramp - this is to make sure the car starts form the same point each time
- Measure the distance between each light gate, you need this to find the car’s average speed
- Let go of the car just before the light gate so that it starts to roll down the slope
- The light gates should be connected to a computer, and when the car passes through each light gate, a beam of light is broken and a tome is recorded by data logging software
- Repeat the experiment several times and get an average time it takes for the car to reach each light gate. This will make your results more reliable
- Using these times and the distances between light gates you can find the average speed of the car on the ramp and the average speed of the car on the runway, just divide the average time taken for the car to travel between light gates by the distance between the gates
What should you do if you do not have light gates?
You could use a stopwatch with a lap function
How could you change this experimental set up?
- You could change different things within this experiment to investigate other factor that might affect the cars motion. Just make sure that if you do change something, every other part of the experiment stays the same
1. You could try seeing if the mass of the car affects its average speed, just load weights onto it (but make sure you do not overload it so the wheel axis grind)
2. To see how friction affect the motion of the car you could try placing different materials on the ramp. If you do this make sure they are laid flat and they do not change the angle of the ramp in any way
3. You could investigate the acceleration of the car due to gravity by starting it off higher up the ramp and seeing how this affects its average speed between the gates
4. You could change the angle of the ramp to see how that affects the car’s speed down the slope
5. You could even try it with different cars to see how size, shape and weight of the car affects how fast it goes down the ramp (you would expect more streamline ones to go quicker)
What apparatus would you need to investigate motion?
- Toy car
- Ramp
- Light gates
- Runway
- Computer
How do you work out the distance travelled on a velocity time graph?
The area between a velocity time graph and the time axis