Find the spring constant for a spring that stretches 1.4cm when a 638 g weight is attached to it. how much work is done as the spring extends?

Spring constant: .

Work done: .

Explanation:

Convert all values to SI units.

Assume that the spring-mass system is vertical and is placed on the surface of the earth. The gravitational acceleration constant will be equal to .

Gravitational pull on the weight:

.

That's also the size of the force on the spring. .

The spring constant is the size of the force required to deshape the spring (by stretching, in this case) by unit length.

.

Assume that there's no energy loss in this process. The work done on the spring is the same as the elastic potential energy that it gains:

.

neutrons are in the middle of the atom and the electrons, which are much smaller.

number of molecules / avogadro's number * molecule molecular = mass

explanation:

we define a gram-molecular weight as the mass of one mole of any element or compound. a mole contains avogadro's number of units (molecules) –  

6.022

x

10

23

. so, dividing the number of molecules by avogadro's number gives us the number of moles. multiplying that by the molecular weight gives us the mass. from the periodic table we find the gram-molecular weight of u to be238 and of f to be19. so,  

u

f

6

will have a gram-molecular weight of 352g.