Answer:
Work done = 13605.44
Explanation:
Data provided in the question:
For elongation of 2.1 cm (0.021 m) work done by the spring is 3.0 J
The relation between Energy (U) and the elongation (s) is given as:
U =
................(1)
where,
k is the spring constant
on substituting the valeus in the above equation, we get
3.0 = 
or
k = 13605.44 N/m
now
for the elongation x = 2.1 + 4.1 = 6.2 cm = 0.062 m
using the equation 1, we have
U = 
or
U = 26.149 J
Also,
Work done = change in energy
or
W = 26.149 - 3.0 = 23.149 J
Answer:
d ≈ 7,6 g/cm³
Explanation:
d = m/V = 40g/5,27cm³ ≈ 7,6 g/cm³
V = l³ = (1.74cm)³ ≈ 5,27 cm³
During a total solar eclipse, the moon passes between Earth and the sun. This completely blocks out the sun’s light. However, the moon is about 400 times smaller than the sun. How can it block all of that light?
Kinetic energy increases, potencial energy decreases,
kinetic energy + potential energy = energy, energy can not be destroyed, just transformed