Investigating into the factors that affect acceleration
I have chosen to investigate the affect changing the amount of force applied to an object has on acceleration.
I predict that as the amount of force applied to the trolley increases, the acceleration will increase in direct proportion. I believe this will happen because according to Newton’s Second Law, increasing the force increases the acceleration, provided the mass stays the same. Therefore, acceleration is directly proportional to the force applied.
Without fair testing the experiment would be useless because the information gathered would not be accurate or reliable. Here are the things we did to ensure our experiment was a fair test:
- The distance travelled; the mass and weight of the trolley shall remain constant, as these are not the factors we will be changing.
- The only thing we will change will be the force applied to the trolley. No force will be applied to the trolley when it is at the top of the runway, instead we will just let go of it and let gravity be the force.
- When putting the trolley at the top of the runway we will make sure that the back wheels of the trolley are touching the ticker timer – this way each experiment will start in the same place.
- We will test the trolley beforehand to ensure all wheels were working, because if one or more wheels are not working this could affect the speed/acceleration of the trolley.
As with all experiment, safety is crucial. Every experiment possesses some form of danger and through these guidelines I hope the risk of danger will be minimised:
- Make sure the trolley is stopped before it reaches the end of the runway where the pulley is to prevent damage to trolley, runway or pulley.
- Make sure that when catching the trolley at the opposite end of the runway you are not in front of it before it reaches a halt as it could cause an injury
For this experiment we shall use a ticker-timer to record our results. A ticker-timer is a way of analysing the motion of objects. As the trolley moves, it drags the tape through the ticker timer, thus leaving a trail of dots, which were printed there by a vibrating metal bar running on an electric current, which hits a piece of paper fifty times a second. The analysis of a ticker tape will reveal if the object is moving with constant velocity or accelerating. This is how we hope to record the acceleration of our trolley. To get the results from the ticker timer tape, you need to divide the tape into five dot strips, this is because each five dots is equal to 0.1 seconds.