Bài 2:
\(\left\{{}\begin{matrix}v'=s':t'=150:\left(0,5.60\right)=5\left(\dfrac{m}{s}\right)\\v''=s'':t''=90:15=6\left(\dfrac{m}{s}\right)\\v_{tb}=\dfrac{s'+s''}{t'+t''}=\dfrac{150+90}{\left(0,5.60\right)+15}=5,3\left(\dfrac{m}{s}\right)\end{matrix}\right.\)
Bài 5:
\(v_{tb}=\dfrac{v'+v''}{2}=\dfrac{10+15}{2}=12,5\left(\dfrac{km}{h}\right)\)
Bài 4:
\(100cm^2=0,01m^2\)
\(p=\dfrac{F}{S}=\dfrac{50.10}{0,01.2}=25000\left(\dfrac{N}{m^2}\right)\)