Question

汽车的速度为7m/s,关闭发动机后做匀减速运动,当汽车前进了100m时速度减为5m/s,若现经过50s,则汽车又前进了多

Answer 1

V平方-Vo平方=2ax,

求得a=0.24m/s^2,

V=Vo+at,

求得t=20.8s,

所以经过50s,汽车早就停下来了.

x=Vot+1/2at^2

=0+1/2*0.24*20.8^2

=52.1m