Calling out for some assistance

[Dozer]

So, I'm doing some work and I'm stuck on these math problems. I haven't done conversions for so long that I actually do not know how to approach these... so O.F.F., anyone here good with numbers that wanna give these a shot and help me out.

4. If this same soil were 68.92 cm thick and with a density of 1.25 g cm-3, how long
would it take to erode away the entire 4.61 acres?

 

[rusty420]

My head actually hurts from just trying to read those!
Sorry.

 

[grubman]

HINT: use the factor lable method.

 

[FishingNoob]

HINT: use the factor lable method.

DAM! How'd you know that!

I've never seen some of the units in those questions...

Sorry Dozer... and math is usually my best course!

 

[Klamp]

1. 12,158,466L using your literal example. But that would never be used to measure rainfall. Rain wouldn't be measured over a 4KM square area, it would be measured in a 20mm area and calculated accordingly.

Clarify number 1 and I'll be able to figure out the real-world numbers for you (after a few drinks). If your catchment area is actually 4 square KM than it's pretty straight-forward.

corrected to your literal measurements **4 km2

 

[ChaseChrome]

So, I'm doing some work and I'm stuck on these math problems. I haven't done conversions for so long that I actually do not know how to approach these... so O.F.F., anyone here good with numbers that wanna give these a shot and help me out.

1. Rain falls onto a 4.0 km2 watershed at a rate of 2 mm hr-1, for a total of 11.5
hours. If water is known to be 1000 L m-3, how many litres of rain fell on the
watershed during the entire rainstorm?


2. If Highland Creek flows out of its watershed (same area as above) at a rate of 4.37
x 10-7 km3 hr-1, what is the total runoff (in mm) over 1.167 days?

3. Soil erodes away from a farmer’s field at a rate of 13.67 metric tonnes ha-1 yr-1.
In 3.05 years, how much soil (in kg) will have eroded from 4.61 acres?

4. If this same soil were 68.92 cm thick and with a density of 1.25 g cm-3, how long
would it take to erode away the entire 4.61 acres?

5. Water is vapourized and blown into a balloon until the total balloon volume is 568
cubic inches. A total of 2.09 L of water vapour was blown in. Presuming
everything is at standard pressure and temperature, 1000 L of water has a mass of
1 metric tonne. What is the density of water vapour in the balloon in units of kg
m-3? If the density of water at saturation vapour pressure under these conditions
is 3 x 102 kg m-3, what is the relative humidity (%) within the balloon?

What the hell is #3 asking man...I did math in University but I'm not understanding your abreviaitons...

 

[grubman]

DAM! How'd you know that!

I've never seen some of the units in those questions...

Sorry Dozer... and math is usually my best course!

Ha ha. In high school they always show you the hardest way to do things then they'll show you the easy way.....lol. Funny education system.

1L/1000ml, 1cm^3=1ml of water both equals 1 as the units cancel out. This is hint #2.......lol.

 

[Dozer]

#1 ----> 2mm/hr

#3 ----> 13.67 metric tonnes/ per hectare per year....

 

[ChaseChrome]

5. Water is vapourized and blown into a balloon until the total balloon volume is 568
cubic inches. A total of 2.09 L of water vapour was blown in. Presuming
everything is at standard pressure and temperature, 1000 L of water has a mass of
1 metric tonne. What is the density of water vapour in the balloon in units of kg
m-3? If the density of water at saturation vapour pressure under these conditions
is 3 x 102 kg m-3, what is the relative humidity (%) within the balloon?

I'm getting .689 kg/m[sup]3[/sup]
[sup]
[/sup]
[sup]Make sense or no??[/sup]

 

[Dozer]

I think I'm going to cry... for #1 I got 92,000 L :blink:

 

[manitoubass2]

hahahaha, this thread got me laughing pretty good!

 

[Klamp]

I think I'm going to cry... for #1 I got 92,000 L :blink:

Thats right. Using the NOAA gauge of 20mm.

20mm rain gauge x 23mm (rain) = 72.28 mm3 (V = pi x r2 x height)

72.28 mm3 of rain / 3.14 mm2 (rain gauge catchment area) = 23.02mm3 of rain per 1 mm2 catchment

Your watershed (catchment area) is 4,000,000,000 mm2

4,000,000,000 x 23.02 mm3 = 92000000000 mm3

92000000000 mm3 = 92,080L

 

[ChaseChrome]

Thats right. Using the NOAA gauge of 20mm.

20mm rain gauge x 23mm (rain) = 72.28 mm3 (V = pi x r2 x height)

72.28 mm3 of rain / 3.14 mm2 (rain gauge catchment area) = 23.02mm3 of rain per 1 mm2 catchment

Your watershed (catchment area) is 4,000,000,000 mm2

4,000,000,000 x 23.02 mm3 = 92000000000 mm3

92000000000 mm3 = 92,080L

yup

 

[ChaseChrome]

It's all multiplication and division bro...
just standardize the units

 

[Klamp]

Funny I'm looking at the series of questions now and see a resemblance to ones I did in engineering. I sure hope you don't have the same professor as the guys who built the Gardner Expessway did. I think he missed a zero somewhere. LOL

 

[NADO]

I didnt read through all of the problems but if conversions is giving you trouble try this program. I use it all the time for work converting volume and distance.

http://joshmadison.com/convert-for-windows/

 

[DanForte]

So, I'm doing some work and I'm stuck on these math problems. I haven't done conversions for so long that I actually do not know how to approach these... so O.F.F., anyone here good with numbers that wanna give these a shot and help me out.

1. Rain falls onto a 4.0 km2 watershed at a rate of 2 mm hr-1, for a total of 11.5
hours. If water is known to be 1000 L m-3, how many litres of rain fell on the
watershed during the entire rainstorm?


2. If Highland Creek flows out of its watershed (same area as above) at a rate of 4.37
x 10-7 km3 hr-1, what is the total runoff (in mm) over 1.167 days?

3. Soil erodes away from a farmer’s field at a rate of 13.67 metric tonnes ha-1 yr-1.
In 3.05 years, how much soil (in kg) will have eroded from 4.61 acres?

4. If this same soil were 68.92 cm thick and with a density of 1.25 g cm-3, how long
would it take to erode away the entire 4.61 acres?

5. Water is vapourized and blown into a balloon until the total balloon volume is 568
cubic inches. A total of 2.09 L of water vapour was blown in. Presuming
everything is at standard pressure and temperature, 1000 L of water has a mass of
1 metric tonne. What is the density of water vapour in the balloon in units of kg
m-3? If the density of water at saturation vapour pressure under these conditions
is 3 x 102 kg m-3, what is the relative humidity (%) within the balloon?

3.
Soil erodes away from a farmer’s field at a rate of 13.67 metric tonnes ha-1 yr-1.
In 3.05 years, how much soil (in kg) will have eroded from 4.61 acres?

4.61 acres = 1.865601 hec

13.67 metric tonnes *1.865601 hec = 25.50277 per year
25.50277 * 3.05 yrs = 77.78344 will have eroded from 4.61 acres in 3.05 years.

i more or less tried for fun very very very high chance its wrong hahah

 

[dcrisci]

So, I'm doing some work and I'm stuck on these math problems. I haven't done conversions for so long that I actually do not know how to approach these... so O.F.F., anyone here good with numbers that wanna give these a shot and help me out.

1. Rain falls onto a 4.0 km2 watershed at a rate of 2 mm hr-1, for a total of 11.5
hours. If water is known to be 1000 L m-3, how many litres of rain fell on the
watershed during the entire rainstorm?


2. If Highland Creek flows out of its watershed (same area as above) at a rate of 4.37
x 10-7 km3 hr-1, what is the total runoff (in mm) over 1.167 days?

3. Soil erodes away from a farmer’s field at a rate of 13.67 metric tonnes ha-1 yr-1.
In 3.05 years, how much soil (in kg) will have eroded from 4.61 acres?

4. If this same soil were 68.92 cm thick and with a density of 1.25 g cm-3, how long
would it take to erode away the entire 4.61 acres?

5. Water is vapourized and blown into a balloon until the total balloon volume is 568
cubic inches. A total of 2.09 L of water vapour was blown in. Presuming
everything is at standard pressure and temperature, 1000 L of water has a mass of
1 metric tonne. What is the density of water vapour in the balloon in units of kg
m-3? If the density of water at saturation vapour pressure under these conditions
is 3 x 102 kg m-3, what is the relative humidity (%) within the balloon?

Are you having troubles carrying out the entire questions or just converting the units of measurement? Because thats two different stories were talking about

If youre having troubles converting units all you really need to know is the conversion factors between them (ex 1 hour has 60 minutes or 3600 seconds)

Just some help out for #1:

You have a 4km squared area, which is getting rained on at a rate of 2mm/hr

You can convert this 2mm/hr into meters per hour which makes it a whole lot easier to work with, giving us 0.002m/hr of rainfall. Also it is raining for 11 and a half hours so... 0.002m/hr * 11.5 = 0.023m of rainfall

Its falling into a watershed which has a surface area of 4km squared, using our amount of rainfall and this area we can find the volume of water raining on the watershed. But before this we need similar units so we either need to convert km to m or m to km. We know 1000m = 1km

4km squared = 4000m squared
to find the volume of water falling into the watershed we will do 4000m squared x 0.023m = 92 m^3

Furthermore, we know that in every m^3 of water there is 1000L
so to finish the question with finding the amount of water which rained onto the water we would multiply 1000 L/m^3 * 92 m^3 = 92000 L of water

which you are correct (i believe)! If im wrong ill be dissappointed im going to school for math and sciences!

EDIT: didnt see someone already fully did the first question for you, i can most certainly help out on other questions too if youd like

 

[Klamp]

Are you having troubles carrying out the entire questions or just converting the units of measurement? Because thats two different stories were talking about

If youre having troubles converting units all you really need to know is the conversion factors between them (ex 1 hour has 60 minutes or 3600 seconds)

Just some help out for #1:

You have a 4km squared area, which is getting rained on at a rate of 2mm/hr

You can convert this 2mm/hr into meters per hour which makes it a whole lot easier to work with, giving us 0.002m/hr of rainfall. Also it is raining for 11 and a half hours so... 0.002m/hr * 11.5 = 0.023m of rainfall

Its falling into a watershed which has a surface area of 4km squared, using our amount of rainfall and this area we can find the volume of water raining on the watershed. But before this we need similar units so we either need to convert km to m or m to km. We know 1000m = 1km

4km squared = 4000m squared
to find the volume of water falling into the watershed we will do 4000m squared x 0.023m = 92 m^3

Furthermore, we know that in every m^3 of water there is 1000L
so to finish the question with finding the amount of water which rained onto the water we would multiply 1000 L/m^3 * 92 m^3 = 92000 L of water

which you are correct (i believe)! If im wrong ill be dissappointed im going to school for math and sciences!

EDIT: didnt see someone already fully did the first question for you, i can most certainly help out on other questions too if youd like

No offense but you gotta check your conversions unless I'm reading your implication wrong - if so carry on. You took square KMs and converted to linear meters.

1KM square is 1,000,000 meters square.

i.e. 1000 meters x 1000 meters = 1,000,000 meters square.

 

[NADO]

No offense but you gotta check your conversions. You took square KMs and converted to linear meters.

1KM square is 1,000,000 meters square.

i.e. 1000 meters x 1000 meters = 1,000,000 meters square.

My convert program verifies this. lol