# Experiment to find the acceleration due to gravity using free fall.

Experiment to find the acceleration due to gravity using free fall

As the title suggests, this experiment is to find the acceleration any object under free fall will undergo when travelling towards the earth. We presume in this experiment that we are unaware of the constant g and the basis of this experiment is to rediscover this value.

Apparatus

The principle behind the circuit is fairly simple. The ball is held through magnetism to the electromagnet; however when the magnetic field is no longer being created i.e. the switch is opened, the ball falls.

When the switch is opened, the timer also starts as the switch is connected to one of its inputs. The ball strikes the metallic plate as it falls and breaks the contact between the metal plate and the rest of the circuit. The plate switch is also connected to the timer which then stops timing.

In this way the time taken for the ball to fall a certain height is measured and hence its acceleration. The height fallen by the ball is measured by moving the plate switch up and down a wooden pole and measuring through use of a tape measure the distance between it and the bottom of the ball.

All distances given in the data were from the top of the metallic plate to the bottom of the steel ball. The distance had to be standardised as the rate of acceleration depends upon the exact distance fallen in a certain amount of time. If we had not worked out two standard points that all our measurements were taken from we would not have been able to calculate the acceleration of the ball to an accurate degree.

The acceleration acting upon the ball as it falls towards the earth is due to gravity. It is therefore prudent to show some understanding of the physics of the experiment before we actually look at the data itself.

All following material is taken from Explaining Physics A-Level Edition by Stephen Pople.

Gravity is a force of attraction between any two masses. This force is unusual as it is the only force discovered that has no repulsive effect unlike for example, magnetism which can attract and repel other masses.

The Earth is surrounded by a gravitational field which exerts a force on any mass in it. In terms of this experiment the ball is attracted towards the earth as it falls.

I read that experiments done in the past have shown that at a particular place all bodies falling freely under gravity in a vacuum or where ...