his is the correct equation for centripetal accelerationacceleration towards the center of motion. In this case it isn't necessary to introduce a numerical factor. Such a factor is often displayed explicitly as a constantkin front of the right-hand side; for example,a=kv²/r.As it turns out,k= 1 gives the correct expression. A good technique sometimes introduced in calculus-based textbooks involves using unknown powers of the dimensions. This problem would then be set up as[a] = [v]^b[r]^c.Writing out the dimensions and equating powers of each dimension on both sides of the equation would result inb= 2andc=1. QUESTIONWhich of the following replacements ofvin the final answer would also give a dimensionally correct equation? (Select all that apply.)

vt / r

r / t

v²t / r

r²/ t

r t