Is 8/20 and 20/80 proportional or not proportional

Acar with a mass of 600 kg is traveling at a velocity of 10m/s. how much kinetic energy does it have?

Sketch one cycle if the cosine function y=2cos2theta

At the beginning of year 1, carlos invests $600 at an annual compound interest rate of 4%. he makes no deposits to or withdrawals from the account. which explicit formula can be used to find the account's balance at the beginning of year 5? what is, the balance?