设小球的初速度为v0,从原点被抛出,
x= v0 t cosa
y=vo t sina - (1/2) g t^2 = x tan a - (gx^2) / [2(v0 cosa)^2]
v0^2 = (gx^2) / [2(x tana - y) (cosa)^2]
代入数据算得 v0= 13.9 m/s
t= x/(v0cosa)
vy=v0sina -gt =vosina -g x/(v0cosa) = - 4.9 (m/s)
vy
设小球的初速度为v0,从原点被抛出,
x= v0 t cosa
y=vo t sina - (1/2) g t^2 = x tan a - (gx^2) / [2(v0 cosa)^2]
v0^2 = (gx^2) / [2(x tana - y) (cosa)^2]
代入数据算得 v0= 13.9 m/s
t= x/(v0cosa)
vy=v0sina -gt =vosina -g x/(v0cosa) = - 4.9 (m/s)
vy