A 60 kg student on ice skates stands at rest on a frictionless frozen pond holding a 10 kg brick. He throws the brick east with a speed of 18 m/s. What is the resulting velocity of the student?

a charge 3q is at the origin, and a charge −2q is on the positive x axis at x=a. part a where on the x-axis would you place a third charge so it would experience no net electric force? enter an expression for the exact answer, which will involve a square-root sign. (do not enter an approximate decimal answer.)