CP1 Accelartation of falling object Flashcards
What are the 3 methods ?
Using an electromagnet (EM)
Using a card down a ramp (RAMP)
Dropping a card for it to fall freely (DROP)
Why use an electromagnet?
Removes human error, as the magnet demagnetises allowing for the ball to drop.
(EM) Why use a trap door?
Ball hits trap door and breaks connection of the circuit stopping the timer
(EM) How do you find g?
Use of s =ut + 1/2 x at^2
so draw a graph of t^2 against h
g is 2(1/gradient)
(EM)How could you reduce the uncertainty?
Use larger distances as there are small t values
Use a lower current so that there is less residual magnetism
(EM)Why isn’t air resistance a factor
not fast enough
(RAMP) How ?
attach a card to the top of the trolley and measure its width
release it and start a stopwatch
calculate final speed using a light gate
v= length of card/ time
(RAMP) What graph is plotted?
v against t with the gradient being g
(RAMP) How to reduce uncertainty?
Use larger distances to increase the small values of t
(RAMP) Problems?
Ar resistance causes a smaller value of v
Friction between the ramp and the wheels
Reaction time when using a stopwatch
(DROP) How?
Get a piece of card and measure the height (h) from its centre to a light gate
Light gate measures the time it takes for the card to pass through
v= length or card/ time
(DROP) Graph?
use of v^2 = u^2 +2as so
v^2 against s
g =gradient/2
(DROP) Reducing uncertainty?
Use larger distances
Attach blue tack at the bottom for a more direct fall path
Reaction time has nor effect due to use of light gates
(DROP) Problems?
Air resistance
What must be done for all?
Vary the distances
Take multiple readings (3 or more) and make a mean
remove any anomalies
