打点计时器的打点时间间隔t=
=1 f
=0.02s,1 50Hz
由图(b)所示纸带可知,碰撞前A的速度:vA=
=xA t
=2m/s,0.0400 0.02
碰撞后A的速度vA′=
=0.97m/s,0.0194 0.02
碰撞后B的速度:vB′=
=d △tB
≈2.86m/s,0.0100 3.5×10?3
碰撞前后系统总动量分别为:
p=m1vA=0.31×2=0.62kg?m/s,
p′=m1vA′+m2vB′=0.31×0.97+0.108×2.86≈0.61kg?m/s,
绝对误差:|
|×100%=|p?p′ p
|×100%=≈1.7%<5%,0.62?0.61 0.62
由此可知,在误差范围内验证了动量守恒定律.
答:在误差范围内验证了动量守恒定律,证明过程如上所述.