How much force is needed to stretch a spring 1.2m if the spring constant is 8.5 N/m?

Astudent is given an assignment to demonstrate diffraction. he takes a photograph of a straw in a glass of water. the straw appears bent at the water level. which best describes this example? a) this is a good example of diffraction. b) this is an example of dispersion and not diffraction. c) this is an example of refraction and not diffraction. d) this is an example of reflection and not diffraction.

10 newton object is placed 3 meters from the fulcrum. at what distance on the other side would you need to place a 15 newton object to balance the lever? show your work!

Find the magnetic field a distance r from the center of a long wire that has radius a and carries a uniform current per unit area j in the positive z direction.