Answer:
80%
Explanation:
Efficiency of machine = work output/work input ×100 %
From question, work output = 20J
Work input = 25J.
Therefore efficiency = 20/25 × 100 %
Efficiency = 20×4 %
Efficiency = 80%
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Answer:
89.6 cm
Explanation:
From the question,
Volume of the rectangular object = Mass/Density.
V = m/D.................. Equation 1
Given: m = 1.278 kg, D = 4.98 g/cm³ = 4980 kg/m³
Substitute into equation 1
V = 1.278/4980
V = 2.57×10⁻⁴ m³.
But,
V = lwh............... Equation 2
Where l = length of the rectangular object, w = width of the rectangular object, h = height of the rectangular object.
make h the subject of the equation
h = V/lw........... Equation 3
Given: V = 2.57×10⁻⁴ m³, l = 0.047 m, w = 0.061 m.
Substitute into equation 3
h = 2.57×10⁻⁴/(0.047×0.061)
h = 0.896 m
h = 89.6 cm
<span>During
an investigation, a student determines that a copper sample has a
density of 8.10 g/ml. What is the students percent error of the accepted
density for copper is 8.96 g/ml
</span>
C. 1.0 mol/kg sodium phosphide (Na3P)<span>
This is because it will produce 4 ions, and thus has the highest molalitiy. (more particles in solution lowers the freezing point)
</span><span>remember if you ever need anything and you dont want to waste points you can just post it on my pfp or message me the question</span>
