







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 graph with 100 vertices 
20071024 

From amarjeet: let g be a graph with 100 vertices numbered 1 to 100. Two vertices i and j are adjacent only if ij=8 or ij=12. The number of connected components
in g are:
1. 8
2. 12
3. 4
4. 25 Answered by Penny Nom and Victoria West. 





The force of a 5000 tonne lorry 
20041027 

From Aaron: A 50 tonne lorry is parked on a slope with a gradient of 4%.
Due to the self weight of the lorry, what is the force
* acting down the slope
* acting normal (at right angles) to the slope Answered by Penny Nom. 

