SAT2物理题An Olympic diver performs a 3.5 somersault.During his dive he uses the tuck position so that he will have(A)larger angular momentum(B)smaller angular momentum(C)larger rotation rate(D)smaller rotation rate(E)longer time in the air但我不知道是为什么,
问题描述：
SAT2物理题
An Olympic diver performs a 3.5 somersault.During his dive he uses the tuck position so that he will have
(A)larger angular momentum
(B)smaller angular momentum
(C)larger rotation rate
(D)smaller rotation rate
(E)longer time in the air
但我不知道是为什么,
答
一旦跳下去,旋转不受阻碍,故角动量守恒,排除ab,又因他蜷缩起身子,转动惯量变小,故角速度要加快以维持角动量不变.故选C（E很显然错.）
在转动力学中,你可以把角动量类比成动量,转动惯量类比成质量,力矩类比成力.而转动惯量的大小是与质量的分布情况有关的：离转动中心越近越小.