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A construction site uses 50m3 sand and gravel, and it is transported by trucks with a loading capacity of 3.5t. How many trucks should be transported at least? (the known density of sand is 2.6 × 103kg / m3)
Given: ρ = 2.6 × 103kg / m3 & nbsp; v = 50m3 & nbsp; M0 = 3.5t, n =? ∵ ρ = MV, ∵ the mass of sand is m = ρ v = 2.6 × 103kg / m3 × 50m3 = 130 × 103kg = 130t, and the number of vehicles to be carried is n = mm0 = 130t3.5t ≈ 38
A construction site needs to transport 140 tons of stones, which has been transported eight times by a 10 ton truck. The remaining stones are transported by a 15 ton truck,
How many more?
(140-10x8) △ 15 = 4 (trip)
A tanker carries 30m3 of oil. Take 30ml of oil out of the tanker and weigh it to be 24.6g. What is the total mass of oil in the tanker?
According to the formula ρ = MV, the density of oil is ρ = m1v1 = 24.6g30cm3 = 0.82g/cm3 = 0.82 × 103kg / m3, and the total mass of oil is m = ρ v = 0.82 × 103kg / m3 × 30m3 = 2.46 × 104kg
A tank car is loaded with 5 cubic meters of oil, from which 30 ml of oil is taken out, and the weight is 24.6 g. how many tons of oil is the weight of this car?
Answer: 4.1 tons
Analysis:
The density of the oil is:
ρ＝m/v＝24.6/30＝0.82g/cm3
That is, ρ = 820Kg / m3
So:
M oil = ρ v = 820 × 5 = 4100Kg = 4.1T
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