Question

m=100kg
F=400N
α= 45°
μ=0,2
g=10 N​

Answer 1

Răspuns:

c) a = F/m = 400/100 = 4 m/s2

Answer 2

b) R=ma

R=Fcosα-Ff

R=ma=>Fcosα-Ff=ma

c)Ff=μN

N-mg+Fsinα=0=>N=mg-Fsinα

Ff=μmg-μFsinα=0,2*100*10-0,2*400*0,7=200-56=144 N

Fcosα-Ff=ma<=>400*0,7-144=100a<=>280-144=100a=>136=100a=>a=1,36 m/s²

d)

N=mg-Fsinα=100*10-400*0,7=1000-280=720 N