mv1 |
qB |
可知动能为:EK1=
1 |
2 |
v | 21 |
q2B2
| ||
2m |
穿过金属板后粒子的速率为v2,轨道半径为:R2=
mv2 |
qB |
可知动能为:EK2=
1 |
2 |
v | 22 |
q2B2
| ||
2m |
动能的减少量为:△EK=EK1−EK2=
q2B2 |
2m |
R | 21 |
R | 22 |
故穿过金属板的次数为:n=
EK1 |
△EK |
| ||||
|
202 |
202−192 |
400 |
39 |
答:穿过金属板的次数10次.
mv1 |
qB |
1 |
2 |
v | 21 |
q2B2
| ||
2m |
mv2 |
qB |
1 |
2 |
v | 22 |
q2B2
| ||
2m |
q2B2 |
2m |
R | 21 |
R | 22 |
EK1 |
△EK |
| ||||
|
202 |
202−192 |
400 |
39 |