如图所示,一根长0.1m的细线,一端系着一个质量为0.18Kg的小球,拉住线的另一端,使球在光滑的水平桌面上作匀速圆周运动,使小球的转速很缓慢地增加,当小球的转速增加到开始时转速的3倍时,细线断开,线断开前的瞬间线的拉力比开始时大40N,求:
—Who is the young man?
—A famous singer. Look! Hundreds of are waiting for him.