一題簡諧運動的問題

M當作自由體來看: x = 向右位移, a = 加速度F1 = M*a向右, F2 = Friction = u*M*g向左=> F1 = F2 => a = u*g同時 F = k*x = (m+M)*a=> x = (m+M)*a/k = (m+M)*u*g/k E = Energy= 0.5*k*x^2 (Spring energy)= 0.5*(m+M)*Vmax^2 (Kinetic energy)=> Vmax = x*√[k/(m+M)]= [(m+M)*u*g/k)]*√[k/(m+M)]= u*g√[(m+M)/k]= (D)

2015-03-03 07:05:33 補充：
M當作自由體來看: x = 向右位移

F1 = M*a向右, F2 = Friction = u*M*g向左

=> F1 = F2

=> a = u*g


同時 F = k*x = (m+M)*a

=> x = (m+M)*a/k = (m+M)*u*g/k


E = Energy

= 0.5*k*x^2 (Spring energy)

= 0.5*(m+M)*Vmax^2 (Kinetic energy)


=> Vmax = x*√[k/(m+M)]

= [(m+M)*u*g/k)]*√[k/(m+M)]

= u*g√[(m+M)/k]

= (D)