已知:V=5×10-4m3 ρ=1.0×103kg/m3 m0=0.2kg g=10N/kg S=5×10-3m2 求:(1)m水=?(2)p=? (1)∵ρ= m V ∴杯子中水的质量为m水=ρV=1.0×103kg/m3×5×10-4m3=0.5kg; (2)杯子对桌面的压强为p= F S = G S = mg S = (m0+m水)g S = (0.2kg+0.5kg)×10N/kg 5×10−3m2 =1.4×103Pa. 答:(1)杯子中水的质量为0.5kg; (2)杯子对桌面的压强为1.4×103Pa.