# Why there is $1/2$ in $KE=(1/2)mv^2$ and Etc [duplicate]

Hello I’m a high school student, my teacher asked the class for why and how there is a 1/2 in (KE=1/2mv^2)&(PE=1/2 k Δx^2)&(PE=1/2 c(Δv)^2)&(KE=1/2 I W).

This is my first time on this site so please if you can help me out