Paper 1 - Light Gates Flashcards
Describe how you can determine the average speed of a moving trolley as it moves down a slope.
When you know the distance that q body moves and time taken - speed = distance ÷ time. -> measuring the distance between two points that the trolley moves past amd dividing it by the time taken to travel between these points, or by using LIGHT GATES to measure the time for which a known length of card breaks a light beam
How do light gates work
- vehicle released front its starting position and is moves down the slope
- light beam cut by card as enters the light gate and the timer stops.
- beam remains cut until the back of the card passes out of the light gate
- when card leaves the light gate, the light beam stops the timer. (Attached to laptop)
Investigating weight affects on acceleration.
- set up light gates
- record velocity and time for different values of mass on the trolley
- work out acceleration by deciding difference in velocity values by the time taken for the card to pass between both gates.
- If you sre changing the mass, the slope or gradient needs to remain the same.
- record table of values using (0) slope and (cm) cardm
- values suggest acceleration of trolley not dependent on mass of trolley and will remain fairly constant throughout.
Apparatus
Trolley, light gates, data logger, card of known length, slope or ramp, masses
Why do we use light gates ?
We can determine the relationship between force, mass and acceleration by varying the masses added to a trolley and measuring the time it takes to pass between two light gates that are a small distance apart.
Dangers of light gate practical
An accelerating mass more than a few hundred grams may be dangerous and may hurt somebody if it hits them
Why do we use light gates to record acceleration.
It is better to use light gates as more accurate than using ruler and a stopwatch
