A horse is running across a field. The horse accelerates at 8.00 m/s2 over a distance of 9.70 m. It runs until its speed is 23.4 m/s and continues at this speed. What was the horse's initial speed?

Answer 1

v = Vi + a t

23.4 = Vi + 8 t

average speed = (Vi+23.4)/2
so
t = 9.7/[ (Vi+23.4)/2 ]

so
23.4 = Vi + 8*9.7/[ (Vi+23.4)/2 ]

solve for Vi