[填空题]
A train traveling at a constant speed rounds a curve of radius 235 m. Asa7pw w ixw g +re25 im(zd/tn)t v*d0c82(ltv lam8+,bbl h+ cbadp suspended from the ceiling swings oab,8hb+ld cb+ut to an angle of 17.5$^{\circ}$ throughout the curve. What is the speed of the train?
