1. Measurement of The Gravity With a Ticker Timer Angelene AS 3
2. <ul><li>Aim </li></ul><ul><li>The aim of this experiment is to measure gravity, g, by investigating the free-fall Motion of steel balls with air resistance. </li></ul><ul><li>Background </li></ul><ul><li>The acceleration of free fall may be determined by an experiment in which the time of fall t of a body between two points a distance s apart is measured. </li></ul><ul><li>If the body falls from rest, we can use g=2s/t2 （ time square ） </li></ul><ul><li>to calculate the value of g . </li></ul>
3. Instruments we need: Retort Stand Metre rule weight drop Ticker timer Ticker tape stopwatch
4. Procedure: a) Thread a length of ticker-tape through a ticker- timer and attach the end to a weight dropper b) Connect the timer to the power supply, switch on. c) Release the ticker-tape, a series of dots appears. Repeat doing so and we get several tapes. d) Stop marking the dots as soon as they start getting closer together. e) Count ten dot-to-dot spaces and cut the tape . Work out the velocity of the first and last dots as well as time.
5. f) draw a horizontal line, as a time square axis, a vertical line, as an s axis, on a piece of gridding paper.
6. g) Sketch the dots on the graph, connect them with a line. Find the gradient of the line. Errors: An error in the mechanical sense was the ticker timer clicking at exactly 1/30 of a second. If it wasn’t the results of this lab could be changed greatly. Another error could be the air resistance. Although not a big factor since this lab was preformed in a controlled environment, this factor is still present. Human error played a huge factor in this lab. Due to human error, the entire results could be false. One error could be the error of measuring. This error could effect the entire lab due to the fact that it is not exact. Another human error is the height at which the object was dropped. One of the objects could have been dropped a little higher or a little lower that the other which will make the acceleration inaccurate.