Cau 3

Ne'm 1 vien da' tu' do cao h xuong dat. Chon goc toa do tai mat dat'

a) Quy dao

x= V.cosa.t

y= h+ V.sina.t - gt^2/2

b)

van toc sau khi nem 1 s

vx= v.cosa

vy= v.sina -gt

V=can(vx^2+vy2)

c) gia toc tt luc cham dat'

at= dv/dt

dt la thoi gian di het quang duong

t= vsin/g + [can(v^2.sin^2a+2gh)]/g

dv giong cau b nhung t = cau c

d)

ban kinh cong R=??

co' an= V^2/R

suy ra R= v^2/an

tai thoi diem cao nhat

at=0

an=a=g

v=vx=v.cosa

R=v^2.cos^2a/g