Question

explain Newton's first second and third law with derivation​

Answer 1

deduction of first law frm second law

according to newtons 2nd law F=ma. if no unbalanced force acts on the body, F = 0,

ma = 0,since m not equal to 0,a = 0

this means that if there is no unbalanced force there is no accelaration for the body .the body will be either at rest or be moving with a uniform velocity this is newton's 1st law

deduction of third law frm second law

consider 2 bodies A and B,let them collide. during collision A exert a force F1 on B for a time delta t and B exert a force F2 on A for the same time delta t

change in linear momentum = force *time

change in linear momentum of B = F1*delta t

change in linear momentum of A = F2 * delta t

total = F1*delta t+F2 * delta t

according to 2nd law a=0

F1*delta t+F2 * delta t = 0

F1 = -F2