Answer:
Work done in stretching the spring = 7.56 lb-ft.
Step-by-step explanation:
Normal length of the spring = 8 in or
ft
=
ft
If the spring has been stretched to 11 inch then the stretched length of the spring is = 11 in
=
ft
Force applied to stretch the spring = 12 lb
By Hook's law,
F = kx [where k is the spring constant and x = length by which the spring is stretched]
12 = k(
)
k = 18
Work done (W) to stretch the spring by
ft will be
W = 
= 
= ![18[\frac{x^{2}}{2}]^{\frac{11}{12}}_0](https://tex.z-dn.net/?f=18%5B%5Cfrac%7Bx%5E%7B2%7D%7D%7B2%7D%5D%5E%7B%5Cfrac%7B11%7D%7B12%7D%7D_0)
= 9(
)²
= 7.56 lb-ft
Answer: c
Step-by-step explanation:
u want to separate it into the two triangles and a rectangle. so the first marked triangle is the first part of the problem then it adds on the rectangle 6(12) then theres that other unmarked triangle because u can see the bottom is 14 when the top is 12 so u take the formula and fill in 1/2(6)(2). i hope this makes sense im bad at explaining things.
Answer:
the greatest common factor of 10 and 70 is 10
Let the marks of Devi be x and Ali be y.
So, the equations:
2y = x <em>and</em> y + 16 = x
So,
2y = y + 16. [ because we know equals are equal to equals]
=> 2y - y = 16
=> y = 16
Check
Ali's marks are half of Devi's marks.
Devi's marks are 16 more than alis.
So, Devi's marks will be 16×2 = 32 and 32 is 16 greater than 16 (16+16=32).