giải
đổi 3tấn=3000kg
ta có: \(Fms=u.mg=0,05.3000.10=1500\left(N\right)\)
có: \(\overrightarrow{Fms}+\overrightarrow{Fk}=m\overrightarrow{a}\)
\(\Leftrightarrow Fk-Fms=ma\)
\(\Leftrightarrow2000-1500=500\)
\(\Leftrightarrow a=\frac{500}{m}=\frac{500}{3000}=\frac{5}{30}m/s^2\)
\(v=v_0+at=at'\)
\(2phut=120s\)
\(\Rightarrow v=\frac{5}{30}.120=20m/s\)