Question

大学物理题，求解

Answer 1

（1）
ω^2 = k / m,
ω = 20 rad/s,
T = 2π / ω = π / 10 s
（2）
x0 = A cosφ , φ = ± π/3
v0 > 0 , φ = - π/3
x = 0.02 cos(20t - π/3)
（3）
v = dx/dt = - 0.02 * 20 sin (20t - π/3)
= 0.4 cos(20t + π/6)