[填空题]
A certain type of automobile can accelerate approh:n)mw 8zqwn(ximately1 jtm3j4ma(z p as shown in the velocity–time graph of Fig. 2–35. (The short flat spots in the curve represen4 apm3jmztj(1 t shifting of the gears.)
(a) Estimate the average acceleration of the car in second gear and in fourth gear. The average acceleration in $2^{nd}$ gear is given by $m/s^2$ The average acceleration in $4^{th}$ gear is given by $m/s^2$
(b) Estimate how far the car traveled while in fourth gear. m