Question

URGENTTTTTTTTTTT dau coroana

l= 5 m
h=2 m
corp paralelipipedic(50x30x30)
densitate=1g/cm³
miu=0,6

care este forta pentru care corpul sa coboare uniform
viteza constanta

Answer 1

μ=0,6
V=50x30x30=45000cm³=0,045m³
ρ=1g/cm³=1000kg/m³

l=5m, h=2m⇒ d=√(l²-h²);

sinα=h/l si cosα=d/l=√(l²-h²)/l


F+Gx=Ffr
F=Ffr-Gx
F=μ*N-G*sinα
F=μ*Gy-m*g*sinα
F=μ*G*cosα-m*g*sinα
F=μ*m*g*cosα-m*g*sinα
F=m*g*(μ*cosα-sinα)
F=V*ρ*g*(μ*cosα-sinα)
F=V*ρ*g*(μ*√(l²-h²)/l-h/l)
F=V*ρ*g*(μ*√(l²-h²)-h)/l

Calcule:
F=0,045*1000*10*(0,6*√(5²-2²)-2)/5≈67,5N