水平速度恒為v0cosa
豎直ma=mga=g
vt=v0sina-gt
當(dāng)豎直速度是0的時(shí)候就到了頂點(diǎn)
gt=v0sina
t=v0sina/g
建立坐標(biāo)系:槍口水平是t,豎直是h
經(jīng)過(guò)v0sina/g的時(shí)間,到了最高點(diǎn),
h=v0sinat-0.5gt^2
=(v0sina)^2/g-(v0sina)^2/2g
=v0sina)^2/2g
頂點(diǎn)坐標(biāo):(v0sina/g,(v0sina)^2/2g)
出發(fā)點(diǎn)(0,0)
當(dāng)速度是向下v0sina的時(shí)候,又回到水平線上,
-v0sina=v0sina-gt
t=2v0sina/g
因此過(guò)(2v0sina/g,0)
設(shè)h=at^2+bt
帶入求值即可
b=v0sina/2
a=-g/4
那么h=-gt^2/4+v0sinat/2
K=lim|Δα/Δs| Δs趨向于0的時(shí)候,定義k就是曲率.
曲率的倒數(shù)就是曲率半徑.
h'=-gt/2+v0sina/2
h'(0)=v0sina/2
K=v0sina/2
1/K=2/v0sina
h'(2v0sina/g)=-v0sina+v0sina/2=-v0sina/2
K=-v0sina/2
1/K=-2/v0sina