3 |
v2 |
R |
Bqd |
m(1+cos30°) |
2(2-
| ||
m |
2(2-
| ||
m |
d |
cos30° |
| ||
R |
1 |
2 |
v | 22 |
B2qd2 |
2mcos230° |
2B2qd2 |
3m |
2B2qd2 |
3m |
T |
6 |
2πm |
Bq |
T |
6 |
2πm |
3Bq |
3 |
3 |
2(2-
| ||
m |
2B2qd2 |
3m |
2πm |
3qB |
3 |
A.m、x一定时,R越大,△F一定越大 |
B.m、x一定时,v越大,△F一定越大 |
C.m、R一定时,x越大,△F一定越大 |
D.m、R一定时,v越大,△F一定越大 |
A.小球从开始下落到刚到达最低点的过程中机械能守恒 | ||
B.从轻绳与钉子相碰到小球刚达到最低点过程,重力的功率先减小后增大 | ||
C.小球刚到最低点速度大小为
| ||
D.小球刚到达最低点时绳中张力为
|
1 |
π |
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