







Calculating volume of concrete, dirt, sand, anything. 
20061117 

From Debbie: [This article contains a special calculator to help you find the volume (for example, the cubic yards) of material required to fill (or empty) a space if you know the length, width and depth.]
We are wanting to pour a 24'x30' slab that is 5" deep. How many cubic yards of cement do we need? Answered by Penny Nom. 





Vectors 
20190906 

From Kayla: Hi!
Due to time constraint issues, we skipped vectors in PreCalc last year. However, I'm attempting to complete my AP Physics summer homework and there are 3 problems with vectors. As I explained, I have no idea even where to begin and as such I need some help.
Problem 1:
A plane flying at 90° at 45 m/s is blown toward 0° at 62 m/s by a strong wind. Find the plane's resultant velocity.
I have tried all sorts of online calculators but none are providing me with a formula I can use to solve this problem on my own.
Problem 2:
If you walk 367 m North and 785 m West what is your total displacement from your original location?
What is the problem asking for when it says displacement?
Problem 3:
A plane travels on a heading of 127.0° at a velocity of 25 km/hr. What are the horizontal and vertical components of the plane's velocity?
As you know already, I have never done vectors so I don't know what horizontal and vertical components of velocity are.
Thank you So Much for your help!! I am struggling!!
 Kayla Answered by Penny Nom. 





Pouring a foundation 
20151127 

From Lisa: Hi im building a house 30ft long 18 ft wide I would like to pour a foundation of 6 inches
deep. How much sand, cement , 1/2" gravel do i need. Answered by Penny Nom. 





A barge of triangular cross section 
20140818 

From tushar: a barge of triangular cross section is 20m long 12 m wide and 6m deep.its floats in SW at a draft if 4m find its displacement Answered by Penny Nom. 





An arrow is shot straight up in the air 
20121206 

From heather: The skywalk is a glass bottomed platform that hangs over the edge of the Grand Canyon and is suspended 4000 feet above the floor of the canyon. If a tourist shot an arrow straight up in the air from the observation platform, the arrow's height could be modeled by H(t) =16^2 + 240 + 4000 where H(t) is the height of the arrow above the canyon floor in feet t seconds after being shot, t>0.
(a) Find H(5) and explain its meaning Answered by Penny Nom. 





Gravel, sand, cement and an equilateral triangle 
20120321 

From saheed: how many tonnes of gravel and sand,bags of cements will be required to concrete 5feet depth/deep of 4feet equilateral triangle? Answered by Harley Weston. 





Displacement 
20111217 

From faisal: a helicopter takes off and travels 300 km due north then returns to its landing field. what is its displacement? Answered by Penny Nom. 





Blocks in a wall 
20110912 

From JOHN: HOW MANY BLOCK WILL IT TAKE TO BUILD A 28*48 HOME, ON A FOOTER THAT IS DONE ALREADY, I WANT TO GO TEN HIGH. Answered by Harley Weston. 





Bags of cement 
20100424 

From Carol: How many bags of portland cement will I need for an area that is 18' x 31' with a thickness of 4".
The bags weigh 94 lbs if that is necessary. Thank you for any help. Answered by Penny Nom. 





3D Vectors 
20080722 

From jenina: 1. The summit of a mountain, 2450m above base camp, is measured on a map to be 4580m horizontally from the camp in a direction 32.4º west of north. What are the components of the displacement vector from camp to summit? What is its magnitude? Choose the x axis east, y axis north and z axis up. Answered by Janice Cotcher. 





How many bags of cement do I need 
20080330 

From Joe: How many bags of cement do I need if I want to extend my carport 6 inches all around?
The carport is 15ft. x 15ft. and the existing slab is 4 inches thick. Answered by Harley Weston. 





How many bags of cement will I need? 
20080115 

From James: I want to extend my front porshe more to the left atleast 14' 1" length wise and 5' 1" width wise with 4" thickness. Now i already decimalized in feet those inches, resulting with 14.08 length and 5.08width and 0.33 of thickness. I then Get my square feet of 71.53. And go on to cubic feet getting a 23.60 in cubic feet. Now i want to convert to cubic yards so i then divide 23.60 into 27 and get 0.87. Now my question is how would i use this to go and buy the necessary bags of cement knowing that a 94 lb. bag of cement is 1 cubic foot of bulk material. To fill 4 inch of thickness and 14' of length and 5 of width? Answered by Stephen La Rocque. 





Mixing cement 
20071009 

From Sandra: How many bags of cement do I need for a floor for a house that is 8meters long, 8meters wide and 50cm deep. Answered by Stephen La Rocque. 





Sand, stone and cement 
20070424 

From Vijai: I have a room with the following dimensions: length=14 feet, width =20 feet and I'd like to pour a floor 6 inches high. What ratio of sand, stone and cement is needed to cover this area. I would really appreciate your help. Answered by Penny Nom. 





Throwing a stone downwards 
20070112 

From Momo: a stone is thrown vertically downward with an initial speed of 14m/s from a height of 65 m above the ground. A) how far does the stone travel in the first 2.0 s? B) what is the stone velocity just before it hits the ground? Answered by Stephen La Rocque. 





How much cement would I need? 
20060907 

From Lou: At a five to one mix how much sand/gravel and how much cement would I need for a 71/2 yard pour?
What formula would I use for this calculation. My sand/gravel is in a cone shaped pile and I know how to calculate that. I need to know if I have enough and how many bags of cement I need to buy. I will be using a engine operated cement mixer Answered by Harley Weston. 





I am pouring cement 
20060822 

From David:
I AM POURING CEMENT
8FT. X 8 FT. X 4 INCHES
8FT. X 8FT. X 5 INCHES.
8FT. X 8FT. X 5 1/2 INCHES.
WHAT IS THE FORMULA?
Answered by Penny Nom. 





How many bags of concrete will we need to use? 
20060720 

From Sue: We are trying to pour some concrete
The area measures 26 ft long x 20 in wide. We want to pour the concrete 3 in thick.
One bag covers .41 cu. ft.
How many bags of concrete will we need to use? Answered by Penny Nom. 





Concrete for a chicken coop floor 
20060713 

From Chelsea: How much concrete for a chicken coop floor? The dimentions are 3 slabs, 30 feet long and 4 inches thick, 6 feet 6 inches wide. One slab is 41 feet long, 6 feet 6 inches wide, and 4 inches thick. Answered by Stephen La Rocque. 





Cement for a large patio 
20060713 

From Jim: I have a 60' by 100' patio. I am wanting to raise it 1 foot. The truck carrying the cement can only hold 10 cubic yards. How many truck loads would I need? Answered by Stephen La Rocque. 





Putting in a sidewalk 
20060531 

From Sandra: I am putting in a sidewalk the measurements are 12 feet by22 inches ,by 4inchs how many bags of cement will I need? Answered by Penny Nom. 





Forty balls are placed in a bag 
20040619 

From Sheila: Forty balls numbered 110 are placed in a bag and four are drawn at random. What is the probability that the first ball drawn is between 110 (inclusive) the second is between 1120, the third is between 2130 and the last is between 3140? Answered by Penny Nom. 





Yards and cubic feet 
20030811 

From Sonya: How many cubic feet are in a yard? Answered by Penny Nom. 





Scoring a college placement test 
20010926 

From Carmen: A college placement test consist of 75 multiplechoice questions, each having 5 possible answers. The exam is scored by subtracting from the number of correct answers onequarter of a point for each question answered incorrectly. If a person answers every question on the exam and scored 45, how many questions were answered wrong? Answered by Penny Nom. 

