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Let us say I have a table in front of me here in my house.- it has a mass of 10 KgOn the table are two rocks - one is 5 Kg and the other is 3 Kg.Gravity acts on the two rocks. The local value for the acceleration due to gravity is near to 10 m/s/sSo the forces acting on the table are about 50N and 30N both acting downwards.So the force due to the weights of the rocks produce a total of 80 N on the table.Well, if the force is 80N and the mass is 10Kg, do you think the table will accelerate downwards at F/M i.e. 80/10 = 8 metres per second per second?Or do you realise that you have to take other forces into account?
OK, the total mass is 18 Kg (3+5+10)and the additional force- the weight of the table is 100 NSo the total force (downward) is 180N, and the total mass is 18Kg.So, do you really think my table is accelerating downwards at 180/10 i.e. 10 m/s/s?Or are you still missing something?
Quote from: Bored chemist on 02/08/2018 07:21:28OK, the total mass is 18 Kg (3+5+10)and the additional force- the weight of the table is 100 NSo the total force (downward) is 180N, and the total mass is 18Kg.So, do you really think my table is accelerating downwards at 180/10 i.e. 10 m/s/s?Or are you still missing something?It has acceleration =0, the floor pushes back against the total force.