Question

求解一道物理题目，急急急急~~英文的

Suppose our Sun eventually collapses into a white dwarf, losing about half its mass in the process, and winding up with a radius 1.0% of its existing radius. Assuming the lost mass carried away no angular momentum, what would the Sun's new rotation rate be? (Take the Sun's current period to be about 30 days.) What would be its final KE in terms of its initial KE of today?

Answer 1

假设我们的太阳最终会坍缩成白矮星，在这个过程中，大约会损失一半的质量，最后的半径是现有半径的1%。假设质量损失不带走角动量，那太阳新的自转速度是多少？ （以太阳目前的周期为30天左右）并根据现有的动能推断出它的最终动能。

我对物理不是太熟悉，希望能帮到你。

Answer 2

质量损失不带走角动量 角动量守恒 Jw=衡量 球体的转动惯量J=2mR²/5 所以新的自传角速度为原角速度的20000倍 所以速度是20000/30rad每天
动能W=Jw²/2 最终动能变为现在的20000倍
我英语不太好。。。