Răspuns:
m=1000kg
v=2m/s
F=10000N
miu=0.3
1.Reprezentam fortele:
ox:F-Ff=ma
oy:N-G=0
10000N-miu*m*g=ma/m
10-miu*g=a
10-3=a
a=7m/s^2.
2.Aflam viteza pe 100m
v^2=vo^2+2ad(Legea vitezei, ecuatia lui galilei)
v^2=2ad
v^2=1400
v=√1400
v=37m/s
3. Aflam energia cinetica:
Ec=mv^2/2
Ec=684.500J
4. Aflam lucrul mecanic al fortei de frecare:
Lm(Ff)=-miu*m*g*d=-3000*100=-300000J
