物理大物作業(yè)答案2014全9

1、2 /4) 22a 2 Acos( T2 /2 /66T 5 取x軸向下x 0.1cos(9.75t) 22 /4) 22a 2 Acos( T2 /2 /66T 5 取x軸向下x 0.1cos(9.75t) 22 cos t 22 1m 1 , 1 02 ,42 2222 以一個(gè)m為坐標(biāo)原點(diǎn)，則另一個(gè)m受到的力則為F=-k2x. d2d2xmF 2kxx0 2 a A2 0.02(4)2 3.16 m am A(4) 2 m kT 2 M k, 00M M kvvtan 0 A x ( ) 22 ,0(M (M k0km或：Imv mv mA(x 1.（1）x x （2）Fdt 0p0000

2、.1 0.23e023t 0.3t ln0.3 v m0 1 0.4 2630.4262.6 1x Acos(t ) 6.48102cos(2t 1.12)第 1 4 Tx 6 A A 2,xyyx462ot5334233130 H3T 4T 020248kv1(k 2,3,2cm/ 4cos10t(x2)Tx 6 A A 2,xyyx462ot5334233130 H3T 4T 020248kv1(k 2,3,2cm/ 4cos10t(x2)x 1 2 0.785 16m 160.12521；Cy3(1) z y(t, 8,t)5cos8t 2z(y, 1 )5cos2 y7 8（2）y A

3、cos(t)， (3)2(x) Ac o s2 t x 2.( ,x22 0.65u2 502 第 2 4 YYu , 24(x,t) 0.05cos(10( ,t)0.05cos(10 )4（2）若反射波的波函數(shù)為y(x,t)0.05cos(10t)，則駐波函數(shù)4y(x,t)y1y2 0.1cos(4 x 2)cos(10t 2) 若反射波的波函數(shù)為y(x,t)0.05cos(10tYYu , 24(x,t) 0.05cos(10( ,t)0.05cos(10 )4（2）若反射波的波函數(shù)為y(x,t)0.05cos(10t)，則駐波函數(shù)4y(x,t)y1y2 0.1cos(4 x 2)cos

4、(10t 2) 若反射波的波函數(shù)為y(x,t)0.05cos(10t4y(x,t)y1y2 0.1cos(4 x 2)cos(10t 2) （3）y(x,t y1 y2 0.1cos4 x 2cos(10t 2波腹 x)1xn x2(2n1)(m),n1,x)0 xnx 4n(m),2y(x,t y1 y2 0.1cos4 x 2cos(10t 2波腹 x)1xn x2(2n1)(m),n0,1,x)0 xnx4n+4(m),n=-2 u 50u 100my(x,t)1.5cos(100tx)(cm) y(x,t)1.5cos(100txAB0,AC 形成與XIX 10I P 4 W/ 29 J 33w6 J 第 3 4 2 300 (W wV wSL 31010 1010 uuD 110 .7m/s 56.5k2 300 (W wV wSL 31010 1010 uuD 110 .7m/s 56.5km/D