Experiments using “optical tweezers” measure the elasticity of individual DNA molecules. For a small enough change in length, the elasticity has the same form as that of a spring. A DNA molecule is an

Experiments using “optical tweezers” measure the elasticity of individual DNA molecules. For a small enough change in length, the elasticity has the same form as that of a spring. A DNA molecule is anchored at one end, then a force of 1.5nN (1x10-9 N) pulls on the other end, causing the molecule to stretch by 5.0 nm (5.0x10-9 m). What is the spring constant of the molecule?