a/ Đổi 100cm= 1m
Có \(\overrightarrow{F_{ms}}+\overrightarrow{P}+\overrightarrow{N}=m.\overrightarrow{a}\)
\(\Rightarrow P.\sin\alpha-F_{ms}=m.a\)
\(\Leftrightarrow mg\sin30^0-\mu.N=m.a\)
Có \(N=-P.\cos30\)
\(\Rightarrow mg\sin30+\mu mg.\cos30=m.a\)
\(\Leftrightarrow10.\frac{1}{2}+0,45.10.\frac{\sqrt{3}}{2}=a\)
\(\Leftrightarrow a=9\left(m/s^2\right)\)
b/ \(v^2-v_0^2=2aS\Leftrightarrow v=\sqrt{2.9.1}=3\sqrt{2}\left(m/s\right)\)