Question

Which statement is true for a car that first goes around a curve of radius r at a constant speed v, and then goes around the same curve at half the original speed?
a) the centripetal force is twice as big the second time around
b) the centripetal force is four times as big the second time around
c) the centripetal force is one-half as big the second time around
d) the centripetal force is one-forth as big the second time around