【評論主題】3. A block of mass 5 kg moving on a frictionless surface with a speed of 3 m/scollides with another

【評論內容】

P=mv

動量守恆

3×5=(5+7)×v

v=15/12=1.25

【評論主題】2. A small ball of mass m is suspended in an elevator by a string of length L. Thestring does not st

【評論內容】

F=kx=m(g+a)

T=2π√(m/k)

k=m(g+a)/X=m(g+a)/L

T=2π√(m/m(g+a)/L

f=1/T=1/2π√(g+a)/L

【評論主題】1. If we denote the dimension of length as [L], dimension of time as [T], anddimension of mass as [M

【評論內容】

F=GMm/R2

[M][L][T]2=G[M][M]/[L]2

G=[L]3[T]2[M]-1