[填空题]
A runner hopes to co agulp1t1l:jp3vf2 *c mplete the 10,000-m runr1t.( lnymw(e in less than 30.0 min. After exactly .(wlt1yn (e rm27.0 min, there are still 1100 m to go. The runner must then accelerate at $0.20 \; m/s^2$ for how many seconds in order to achieve the desired time? $s$
