The strain energy stored in a linear spring is
SE = (1/2)*k*x²
where
k = the spring constant
x = the extension (or compression) of the spring
Given:
k = 470 N/m
x = 17.0 cm = 0.17 m
Therefore
SE = 0.5*(470 N/m)*(0.17 m)² = 6.7915 J
Answer: 6.8 J (nearest tenth)
In short, those arms are made of "stars, dust and gas". They are visible as spiral arms because they have a higher density of those objects than the space between them.
The arms are an area where the density of stars (and planets and other objects) is unusually high and where the start are young - recently formed- and this also gives those starts their visibility as young starts are also very bright.
Answer:
1.5 m/s²
Explanation:
For the block to move, it must first overcome the static friction.
Fs = N μs
Fs = (45 N) (0.42)
Fs = 18.9 N
This is less than the 36 N applied, so the block will move. Since the block is moving, kinetic friction takes over. To find the block's acceleration, use Newton's second law:
∑F = ma
F − N μk = ma
36 N − (45 N) (0.65) = (45 N / 9.8 m/s²) a
6.75 N = 4.59 kg a
a = 1.47 m/s²
Rounded to two significant figures, the block's acceleration is 1.5 m/s².
Usually the coefficient of static friction is greater than the coefficient of kinetic friction. You might want to double check the problem statement, just to be sure.
