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Finding acceleration due to gravity: Deconstruct - Coggle Diagram

- - - - Random Error
        
        A random error that could occur is the inaccurate timing of the period of the pendulum (time it takes for the pendulum to swing from the left to right and back to the original spot on the left) as it can be difficult to know when to stop the stopwatch at the exact time. The effect of this can be decreased by timing the period multiple times and finding an average.
      - Difficult to control the swing of the pendulum
        
        When doing this experiment, the pendulum must only swing from left to right and cannot also have a forwards and backwards motion. This could be difficult to control if the pendulum consists of a weight and thread but can be fixed by replacing the thread with a rod which is rigid and thus, only allows the pendulum to swing from left to right.
      - access to equipment
        
        it may be difficult to get access to equipment such as the pendulum with the rod and a string and weight would have to be used instead. However, as mentioned above, the string and weight would not be as accurate as the rod.
      - results are very sensitive to errors/mistakes
        
        For this experiment to be valid, the period has to be almost exact which is difficult to do due to human reflex error. This is unavoidable and can only be taken into account by increasing sample size (see random error).
    - - A pendulum ideally consisting of a weight and rod (but if not available, a weight and string) is swung from a set angle at least three times. Each time, the period is calculated. The average of the periods is determined (seconds) and put into the equation. The length (l) of the pendulum is measured and also put into the equation. The equation is then solved for 'g' which determines the acceleration due to gravity.
- - - - Inaccurate Spring Balance:
        
        Prolonged use of a spring balance can cause the springs to stretch and give inaccurate results. In order to decrease the impact of this error, multiple spring balances can be used to calculate the mass of the object from which, the average of these results will be used in the experiment.
    - - The weight of an object is determined using multiple spring balances. The average of the weights is calculated. This value takes the place of the "F" in the formula. The mass is calculated using a scale. This number replaces the 'm'. The acceleration due to gravity will then be determined by rearranging the formula and dividing 'F' by 'm'.
- - - - Random Error
        
        Random errors can include things such as the object not being dropped exactly at the required height or the initial velocity not being 0 as force is accidentally applied when releasing the object. Their impact can be reduced by timing the drops multiple times and using average values. The use of technology to construct the velocity-time graph will also minimise human error. Because of this, a motion sensor will be used
      - Air Resistance
        
        Ideally, this experiment would be performed in a vacuum chamber where air resistance would be eliminated. However, this equipment is not readily available and therefore, is not an option. As the surface area of the objects increase, the effect of air resistance will also increase, thus, slowing down the object's acceleration and skewing the results. This can be minimised by using smaller objects such as small weights
    - - Weights of varying masses (10g, 30g) are dropped from varying heights (e.g. 1m, 2m) at least 3 times each to form three separate velocity-time graphs. This would be done using a Pasco motion sensor situated at the landing zone, facing upwards.The slope of each graph would be calculated to find the acceleration (slope formula would be the same as the acceleration formula). The averages of the slope of each graph would be calculated to determine the acceleration due to gravity for each object. This would also explore the effect of height and mass on acceleration.