[填空题]
At the instant a race began,rmene*n.f 56r y(.eow04 j1 z5dtzaao a 5/)tgebz*hl d+qtyc - 65$-\mathrm{kg}$ sprinter exerted a force of 720 N on the starting block at a 22$^{\circ}$ angle with respect to the ground. (a) What was the horizontal acceleration of the sprinter? (Keep one decimal place)
(b) If the force was exerted for 0.32 s , with what speed did the sprinter leave the starting block? (Keep one decimal place)
