A physicist grabs the ends of a DNA strand with optical tweezers and stretches it 28 . How much energy is stored in the stretched molecule if its spring constant is 0.046 ?

To calculate the energy stored in a stretched molecule using Hooke's law, you need to know the value of the spring constant and the amount the molecule has been stretched.

In this case, the spring constant (k) is given as 0.046 N/m, and the molecule has been stretched by 28 nm (0.028 m).

The energy stored in a spring can be calculated using the formula:

E = (1/2)kx^2,

where E represents the energy stored in the spring, k is the spring constant, and x is the displacement of the stretched object.

Plugging in the given values, we have:

E = (1/2)(0.046 N/m)(0.028 m)^2.

Calculating this expression, we find:

E ≈ 0.0000239 J.

Therefore, the energy stored in the stretched molecule is approximately 0.0000239 Joules.