普通物理学下册答案.docx
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普通物理学下册答案
普通物理学下册答案
【篇一:
普通物理学习题答案全】
txt>第一章力和运动....................................................-3-
1-2........................................................................................................................................-3-1-4........................................................................................................................................-4-1-5........................................................................................................................................-6-1-6........................................................................................................................................-6-1-9........................................................................................................................................-7-1-14......................................................................................................................................-8-
第二章运动的守恒量和守恒定律......................-10-
2-3......................................................................................................................................-10-2-9......................................................................................................................................-11-2-11....................................................................................................................................-11-2-13....................................................................................................................................-12-2-16....................................................................................................................................-13-2-17....................................................................................................................................-15-2-19....................................................................................................................................-16-2-23....................................................................................................................................-17-2-27....................................................................................................................................-17-
第三章刚体的定轴转动......................................-18-
3-1......................................................................................................................................-18-3-3......................................................................................................................................-19-3-6......................................................................................................................................-20-3-7......................................................................................................................................-20-3-10....................................................................................................................................-21-3-11....................................................................................................................................-21-
第四章狭义相对论基础......................................-23-
4-1......................................................................................................................................-23-4-8......................................................................................................................................-23-4-11....................................................................................................................................-24-
第五章静止电荷的电场......................................-25-
5-1......................................................................................................................................-25-5-5......................................................................................................................................-26-5-7......................................................................................................................................-26-5-13....................................................................................................................................-27-5-15....................................................................................................................................-28-5-17....................................................................................................................................-30-5-26....................................................................................................................................-31-5-29....................................................................................................................................-32-5-30....................................................................................................................................-33-5-31....................................................................................................................................-33-
5-43....................................................................................................................................-34-
第六章恒定电流的磁场......................................-35-
6-1......................................................................................................................................-35-6-4......................................................................................................................................-36-6-5......................................................................................................................................-36-6-7......................................................................................................................................-37-6-12....................................................................................................................................-38-6-15....................................................................................................................................-39-6-19....................................................................................................................................-39-6-23....................................................................................................................................-40-6-26....................................................................................................................................-41-6-28....................................................................................................................................-42-
第七章电磁感应电磁场理论..........................-43-
7-2......................................................................................................................................-43-7-5......................................................................................................................................-45-7-7......................................................................................................................................-46-7-14....................................................................................................................................-46-7-15....................................................................................................................................-47-7-16....................................................................................................................................-47-
第一章力和运动
1-2
1-4
【篇二:
普通物理学第二版第二章参考答案】
xt>2.1.1质点的运动学方程为
?
?
?
?
(1).r?
(3?
2t)i?
5j,
(2).r?
(2?
3t)?
i?
(4t?
1)?
j
求质点轨迹并用图表示。
解,①.x
?
3?
2t,y?
5,轨迹方程为y=5
?
x?
2?
3t?
y?
4t?
1消去时间参量t得:
3y?
4x?
5?
0
②?
?
?
2t2t
?
?
?
r?
ei?
ej?
2k2.1.2质点运动学方程为,
(1).求质点
的轨迹;
(2).求自t=-1至t=1质点的位移。
?
x?
e
?
2t?
y?
e?
z?
2解,①?
?
2t
消去t得轨迹:
xy=1,z=2
?
?
2?
2?
22
?
?
?
?
?
?
r?
ei?
ej?
2kr?
ei?
ej?
2k②?
1,?
1,
?
?
?
?
222?
2?
r?
r?
1?
r?
1?
(e?
e)?
i?
(e?
e)?
j
?
2
?
?
r?
4ti?
(2t?
3)j,2.1.3质点运动学方程为
(1).求质点
的轨迹;
(2).求自t=0至t=1质点的位移。
解,①.x?
4t,y?
2t?
3,消去t得轨迹方程
2
x?
(y?
3)
?
?
?
?
?
?
?
?
?
?
r?
3j,r?
4i?
5j,?
r?
r?
r?
4i?
2j110②0
2.2.1雷达站于某瞬时测得飞机位置为
2
r1?
4100m,?
1?
33.7,0.75s后测得
r2?
4240m,?
2?
29.3,r1,r2均在铅直平面内。
求飞机
解,
?
?
r?
r1?
r2?
2r1r2cos(?
1?
?
2)
22
代入数值得:
?
?
r?
4100
2
?
4240
2
?
2?
4100?
4240cos4.4
?
349.385(m)
?
?
r349.385v?
?
?
465.8(m/s)
?
t0.75
利用正弦定理可解出?
?
?
34.89
2.2.2一小圆柱体沿抛物线轨道运动,抛物线轨道为
y?
x/200
2
(长度mm)。
第一次观察到圆柱体在
x=249mm处,经过时间2ms后圆柱体移到x=234mm处。
求圆柱体瞬时速度的近似值。
解,
v?
?
?
r?
t
?
(?
x)?
(?
y)
?
t
22
?
15?
36.225
2
22
?
19.6mm/ms
?
?
?
112.5
2.2.3一人在北京音乐厅内听音乐,离演奏者17m。
另一人在广州听同一演奏的转播,广州离北京2320km,收听者离收音机2m,问谁先听到声音?
声速为
340m/s,电磁波传播的速度为3.0?
10解,
8
m/s。
?
t1?
?
t2?
17340
?
0.05(s)
3
2320?
103.0?
10
8
?
2340
?
0.0136(s)
?
t2?
?
t1
在广州的人先听到声音。
2.2.4如果不允许你去航空公司问讯处,问你乘波音
747飞机自北京不着陆飞行到巴黎,你能否估计大约用多少时间?
如果能,试估计一下(自己找所需数据)。
?
t?
解,
?
sv
2.2.5火车进入弯道时减速,最初列车向正北以90km/h速率行驶,3min后以70km/h速率向北偏西30方向行驶。
求列车的平均加速度。
解,
?
00v1?
90?
j,2?
?
70cos60?
i?
70cos30?
j,?
?
?
00?
v?
v2?
v1?
?
70cos60?
i?
(70cos30?
90)?
j
?
22?
v35?
29.3782
a?
?
?
913.91(km/h)
?
t0.05?
0.071(m/s)913.91?
0.05
sin30
?
70sin?
sin?
?
0.7659,?
?
49.99
为正常数。
求
?
?
?
?
r?
rcosti?
rsintj?
2tk2.2.6
(1)r
?
23?
?
?
r?
3ti?
4.5tj?
6tk求t=0,1时的速度和加速度(写出
正交分解式)。
解:
(1)
?
r?
rcos
?
?
drv?
?
dt?
?
dva?
?
dt
?
t?
i?
rsint?
j?
2tk?
?
rsint?
i?
rcost?
j?
2k?
rcost?
i?
rsint?
j
当t=0时,
?
?
?
?
v?
rj?
2k,a?
?
r?
i,vx?
0,vy?
r,vz?
2,ax?
?
r,ay?
az?
0
【篇三:
2012-2013
(1)普通物理学
(2)期中考试试卷与答案】
大学2012-2013学年第一学期
普通物理
(2)试卷(期中)(闭卷)
一、(本题10分)
如图所示,细导线上均匀分布着线密度为?
的正电荷。
已知两段直导线的长度和半圆环导线的半径都等于r,试求环中心o点处的场强和电势。
解:
如下图所示,由于电荷均匀分布与对称性,ab和cd段电荷在o点产生的场强互相抵消。
在半圆环上任取dl?
rd?
,则dq?
?
rd?
在o点产生的de由于对称性,
ex?
0,o点场强沿y轴负方向
?
?
?
?
r