在真空中水平放置平行板电容器,两极板间有一个带电油滴,电容器两板间距为d,当平行板电容器的电压为U 0

2025-05-23 05:42:48
推荐回答(1个)
回答1:

(1)油滴静止时           mg=q
U 0
d

则                         
q
m
=
dg
U 0

(2)设第一个△t内油滴的位移为x 1 ,加速度为a 1 ,第二个△t内油滴的位移为x 2 ,加速度为a 2 ,则
x 1 =
1
2
a 1 t 2
x 2 = v 1 △t-
1
2
a 2 t 2

且            v 1 =a 1 △t,x 2 =-x 1                                  
解得          a 1 :a 2 =1:3                                        
(3)油滴向上加速运动时: q
U 0 +△ U 1
d
-mg=m a 1
,即 q
U 1
d
=m a 1

油滴向上减速运动时 mg-q
U 0 +△ U 1 -△ U 2
d
=m a 2
,即 q
U 2 -△ U 1
d
=m a 2

则                         
U 1
U 2 -△ U 1
=
1
3

解得                           
U 1
U 2
=
1
4