mv1 |
qB |
可知動能為:EK1=
1 |
2 |
v | 21 |
q2B2
| ||
2m |
穿過金屬板后粒子的速率為v2,軌道半徑為:R2=
mv2 |
qB |
可知動能為:EK2=
1 |
2 |
v | 22 |
q2B2
| ||
2m |
動能的減少量為:△EK=EK1?EK2=
q2B2 |
2m |
R | 21 |
R | 22 |
故穿過金屬板的次數(shù)為:n=
EK1 |
△EK |
| ||||
|
202 |
202?192 |
400 |
39 |
答:穿過金屬板的次數(shù)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 |