Answer:
anything but 2
Step-by-step explanation:
f(-1/2)
If you plug in 2, you'd get -1. But if you plug in other values, it won't be equal to -1.
= 1/2kx2
U = potential energy of a spring at a certain position
k = the spring constant, specific to the spring, with units N/m.
x = distance the spring is stretched or compressed away from equilibrium
Potential Energy: Elastic Formula Questions:
1) A spring, which has a spring constant k = 7.50 N/m, has been stretched 0.40 m from its equilibrium position. What is the potential energy now stored in the spring?
Answer: The spring has been stretched x = 0.40 m from equilibrium. The potential energy can be found using the formula:
U = 1/2kx2
U = 1/2(7.50 N/m)(0.40 m)2
U = 0.60 N∙m
U = 0.60 J
Answer:4
Step-by-step explanation:
Ahh, this question goes all the way back to my year 9 test a couple years ago; which I got wrong back then - I now know how
Firstly we find the expression for the area (using x as the walk way):
>50x * 2 (the left and right)
>20x * 2 (the top and bottom)
>4 * x^2 (the corners)
Add them all together , Area = 140x + 4x^2
Now we place the deck's area, <u>456</u> into the expression
456 = 140x + 4x^2
Solve for x
I'm a bit rusty on this i'm afraid, but I believe the only way to solve this is to factorise it
0 = 4x^2 + 140x - 456
0 = 4(x+38)(x-3) <
<u>x must = -38 or = +3 (the numbers inside the brackets inverted)</u>
x must = +3 as it's logical, you can't have a negative width
The walkway is 3 feet wide, we can put this into our expression to double check this,
<em>456 = 140*(3) + 4(3)^2</em>
<em>456 = 420 + 4*9</em>
<em>456 = 420 + 36</em>
<em>456 = 456
</em>Yes, 3 feet wide is correct.
*Note, I tried to keep this simple, please let me know if I didn't go into enough detail anywhere
