[填空题]
Estimate the average acceleration of-y ch)pc,dz,a+ s q/ma t/f(7 or r(grmdhe car in the previous Problem (Fig. 2–35) when it o r(rr/f mdg(7is in
(a) first, $m/s^2$
(b) third, $m/s^2$
(c) fifth gear. $m/s^2$
(d) What is its average acceleration through the first four gears? $m/s^2$