40033444

F α Mm/R² ( 這個α是正比的意思)
2m²/AC² = m²/CB²
2/AC² = 1/CB²
AC²/CB²=2
AC/CB=√(2)
令AC=(√2)k, CB=k
把k代掉
(1+√2)k = d
k = d/(1+√2) = -(1-√2)d = ((√2)-1)d
AC+CB=d
AC=(2-√2)d

40033444

W(F)=F△xcosθ=40x10x1=400
f=μN=2
10μ=2, μ=0.2
f=0.2x100=20
W(f)=f△xcosθ=20x10x(-1)=-200
W(∑F)=W(F)+W(f)=200

40033444

F=mg, F=GMm/R²
g=GM/R², g α M/R²

D=M/V
DV=M
D(4πR³/3)=M

g α (4πR³D/3) / (R²)
g α (4πRD/3)
g α RD
g = (1/2)(4) = 2
這個2是變2倍的意思

40033444

W(F)=F△xcosθ=10x10x1=100
F不是40嗎?
33144653 發表於 2017-12-4 09:53

筆誤 抱歉
已更正