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:
a = 9.849
b = 20.25
c = 491.03
Step-by-step explanation:
By using Pythagoras theorem in the right triangle BDC,
(Hypotenuse)² = (Leg 1)² + (Leg 2)²
BC² = BD² + DC²
a² = 9² + 4²
a = 
a = 
a = 9.8489
a ≈ 9.849 units
By mean proportional theorem,

AD × DC = BD²
b × 4 = 9²
b = 
b = 20.25 units
BY Pythagoras theorem in ΔADB,
AB² = AD² + BD²
c² = b² + 9²
c² = (20.25)² + 9²
c² = 410.0625 + 81
c = 491.0625
c = 491. 063 units
The mean is 52 because 42+45+58+63=208 then you divide it by the amount of numbers: 4 : 208 divided by 4= 52
Answer:
C ig.
Step-by-step explanation:
well, it's not a right angle (90 degrees), it's not a 45 degree angle, and it's not a straight angle (180 degrees), so it's not enough info