Question

一质点沿一直线运动,先以10m/s2的速度匀速前进3S,接着又以2.5m/s2的加速度匀加速运动4S,最后以大小为10m

Answer 1

(1) 10*3 + (10*4 + 0.5(2.5)*4^2) + (20*2 - 0.5(10)(2^2) m

(2) t = 2 sec since v+at = 0,v = 10+2.5*4 = 20,a = 10