2.5
mgh=mgL*(1-cos(alpha))=mv^2/2
h=L*(1-cos(alpha))=5*(1-cos(pi/3))=
2,5 м
mgL*(1-cos(alpha))=mv^2/2
v^2=2gL*(1-cos(alpha))
ma=mv^2/L=F-mg
F=m(v^2/L+g)=m(2gL*(1-cos(alpha))/L+g)=mg(3-2cos(alpha))=100*9,8*(3-2*cos(pi/3)) Н =
1960 Н
2.6
m1v1+m2v2=(m1+m2)*u
v2=((m1+m2)*u-m1v1)/m2=u+m1(u-v1)/m2=0,24+20*(0,24-0,3)/30 м/с=
0,2
м/с