(a) One of the fastest land animals of North America is the pronghorn antelope. (a) If a pronghorn antelope accelerates from rest in a straight line with a constant acceleration of 1.7 m/s², how much time does it take for the antelope to reach a speed of 22 m/s? 

(b) The total frictional force exerted on the antelope by the ground is 78 N. What is the antelope’s mass?