Answer:
13.896 kg
Step-by-step explanation:
You can find the mass of the bar by first finding the volume.
V = BH
where B = area of the base (the trapezium), and
H = height (distance trapezium between bases)
The area of a trapezium is
A = (b1 + b2)h/2
where b1 and b2 are the lengths of the bases of the trapezium (the parallel sides), and
h = the altitude of the trapezium (distance between the bases of the trapezium)
V = (b1 + b2)h/2 * H
V = (12 cm + 6 cm)(5 cm)/2 * 16 cm
V = 720 cm^3
The volume of the bar is 720 cm^3.
Now we use the density and the volume to find the mass.
density = mass/volume
mass = density * volume
mass = 19.3 g/cm^3 * 720 cm^3
mass = 13,896 g
Now we convert grams into kilograms.
1 kg = 1000 g
mass = 13,896 g * (1 kg)/(1000 g)
mass = 13.896 kg
Answer: 1.3896 kg
Im not that good with these types of problems but i think it is b if my math is correct.
Answer:
1) 
2) After 8 minutes delivering fuel the tanks will have 121 gallons of fuel
Step-by-step explanation:
1) For generating the equation we have to take into account that in the tanks there is a initial volume of fuel that corresponds to 75 gallons, as it is stated that tank one is half full. As the capacity for tank 1 is of 150 gallons, half of the tank equals to:

Now we have to convert the rate of delivery that is expressed as a mixed number to an improper fraction so:

Then the pumping rate is of 23/4 gallons per minute, to get how many gallons are in the tank we just need to multiply this rate by the time in minutes, and as there is an initial volume we have to add it, so we have the following equation:

2) To know how much fuel is in the tank after 8 minutes we have to replace this time in the previous equation so we have

After 8 minutes delivering fuel the tanks will have 121 gallons of fuel
Answer: x=14.4
Step-by-step explanation: