A child is swinging a swing. Maximum and minimum heights of the swing from ground are $2 \mathrm{m}$ and $0.75 \mathrm{m}$ respectively. Find the maximum velocity of the swing. $\left(g=10{ \mathrm{ms}}^{-1}\right)$

State Newton's $2^{nd}$ law of motion and show how it leads to

(i) Force$=$mass$\times$acceleration.

State Newton's $2^{nd}$ law of motion and show how it leads to

(ii) Show how Newton's $1^{st}$ law follows from $2^{nd}$ law.