1) E=1/2*m*v^2 >>> v=sqrt(2*E/m)=sqrt(2*20J/0,004kg)=sqrt(10000J/kg)=100m/s
2) E=1/2*m*v^2 >>> m=2*E/(v^2)=2*200J/(16m^2/s^2)=25kg 3)E(kin)=1/2*m*v^2=s*µ*m*g=s*F(Reibung)=s*µ*F(G)
>>>v=sqrt(2*s*µ*g)=sqrt(2*15m*0,8*9,81m/s^2)=15,3m/s
4) 1/2*m*v^2=s*µ*m*g
>>>µ=1/2*v^2/g*s=1/2*(108km/h)^2 /((9,81m/s^2)*50m)=0,9
|