It takes 500 j of work to compress a spring 10 cm. what is the force constant of the spring? (b) when a 3.0 kg block is pushed against a massless spring of force constant 4.5. 10' n/m, the spring is compressed 8.0 cm. the block is released and it slides 2.0 m from the point at which it is released across a horizontal surface before friction stops it. what is the coefficient of kinetic friction between the block and the surface?

Explanation:

a) Energy stored in spring = 1/2 k x² = .5 x k 0.1²

500 = 5 x 10⁻³ k ,

k = (500/5) x 10³ = 10⁵ N/m

b )

k = 4.5 x 10¹ = 45 N/m

Stored energy = 1/2 k x² = .5 x 45 x 8² x 10⁻⁴ =1440 x 10⁻⁴ J

This energy gets dissipated by friction .

work done by friction = μ mg d

d is the distance traveled under friction

so 1440 x 10⁻⁴ = μ x 3 x 9.8 x 2

μ = 245 x 10⁻⁴  or 0.00245 which appears to be very small. .

they are non-matter

explanation:

they are non-matter. basically, any type of energy or any abstract concept is an example of something that does not matter. other examples include dreams, magnetism, radio, and hate

c.the charges if the proton and electron and gravity