[填空题]
Estimate the average acceleration of thprfjpmnj4*9k-ls3l8 e car in the previous Pfp v;lfhz; 8j;fv72cwroblem (Fig. 2–35) when it ;f78 ffpz2vvcj ;wl;h is 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? $m/s^2$