Question

The potential energy, P, in a spring is represented using the formula P = 1/2kx2. Lupe uses an equivalent equation, which is solved for k, to determine the answers to her homework. Which equation should she use?
k = 2Px2
k = 1/2Px2
k = 2p/x^2
k = p/2x^2

Answer 1

Answer:

$k=\frac{2P}{x^2}$

Step-by-step explanation:

The formula is $P=\frac{1}{2}kx^2$

We need to solve for $k$, so we can perform the steps shown below:

$P=\frac{1}{2}kx^2\\P=\frac{kx^2}{2}\\2P=kx^2\\\frac{2P}{x^2}=k$

Hence, the third answer choice is correct.

Answer 2

We need to find a way to get k by itself so lets get it by itself.
For convenience I will switch the equal sign.
1/2kx^2 = p
Multiply both sides by 2
kx^2 = 2p
divide by x^2
k = 2p/x^2