题目
[9-8-3]若简谐振动方程为x=0.10cos (20pi t+0.25pi ),式中x的单位mt的单位s,则t=2 s时的位移,速度和加速度为()A. 7.07times 10^-2 m 4.44 m/s-2.79times 10^2 m/s^2 B. -7.07times 10^-2 m 4.44 m/s-2.79times 10^2 m/s^2 C. 7.07times 10^-2 m-4.44 m/s-2.79times 10^2 m/s^2 D. -7.07times 10^-2 m-4.44 m/s 2.79times 10^2 m/s^2
[9-8-3]若简谐振动方程为x=0.10\cos (20\pi t+0.25\pi ),式中x的单位mt的单位s,则t=2\ \ s时的位移,速度和加速度为()
A. $$ 7.07\times 10^-2\ \ m 4.44\ \ m/s-2.79\times 10^2\ \ m/s^2\ \ $$
B. $$ -7.07\times 10^-2\ \ m 4.44\ \ m/s-2.79\times 10^2\ \ m/s^2\ \ $$
C. $$ 7.07\times 10^-2\ \ m-4.44\ \ m/s-2.79\times 10^2\ \ m/s^2\ \ $$
D. $$ -7.07\times 10^-2\ \ m-4.44\ \ m/s 2.79\times 10^2\ \ m/s^2\ \ $$
题目解答
答案
A. $$ 7.07\times 10^-2\ \ m 4.44\ \ m/s-2.79\times 10^2\ \ m/s^2\ \ $$