Gravity around the earth – why are you heavier at the equator?

After some research,i realise that you are NOT heavier in the equator as compared to the both poles because of centripetal acceleration you will weigh a tiny amount less at the equator than at the poles. Objects which are in motion like to go in a straight line and so it takes some force to make them go round in a circle. So some of the force of gravity is being used to make you go round in a circle at the equator (instead of flying of into space) while at the pole this is not needed. The centripetal acceleration at the equator is given by 4 times pi squared times the radius of the Earth divided by the period of rotation squared (4 timed pi2 times r/T2). The period of rotation is 24 hours (or 86400 seconds) and the radius of the Earth is about 6400 km. This means that the centripetal acceletation at the equator is about 0.03 m/s2 (metres per seconds squared). Compare this to the acceleration due to gravity which is about 10 m/s2 and you can see how tiny an effect this is - you would weigh about 0.3% less at the equator than at the poles!


There is a second reason that you are slightly lighter standing on the equator than at either the North or South pole.
The Earth is not a perfect sphere and is squashed because it is rotating.
Its equatorial radius is about 22 kilometres more than its polar radius.
When standing at a pole you are actually slightly nearer the centre of the Earth than on the equator as gravity reduces as distance increases and although this is very small it is a contributing factor. Incidentally you are slightly lighter when the Moon is overhead (tugging upwards on you like the tides) and heavier when it is the other side of the Earth pulling you downwards. Maybe ranging as much as 1 gram for the average person.

Hence,this is why i say that we weigh lighter on the equator as compared to the poles or countries near them.Thank you for your kind attention.