A 1.40 kg object is held 1.15 m above a relaxed, massless vertical spring with a force constant of 300 N/m. The object is dropped onto the spring.
How far does the object compress the spring?
Repeat part (a), but now assume that a constant air-resistance force of 0.600 N acts on the object during its motion.
How far does the object compress the spring if the same experiment is performed on the moon, where g = 1.63 m/s2 and air resistance is neglected?

Respuesta :

Answer:

a) [tex]\Delta x =0.32433\ m= 324.33\ mm[/tex]

b) [tex]\delta x=0.087996\ m=87.996\ mm[/tex]

c) [tex]\delta x=0.13227\ m=132.27\ mm[/tex]

Explanation:

Given:

  • mass of the object, [tex]m=1.4\ kg[/tex]
  • height of the object above the spring, [tex]h=1.15\ m[/tex]
  • spring constant, [tex]k=300\ N.m^{-1}[/tex]

a)

When the object is dropped onto the spring whole of the gravitational potential energy of the mass is converted into the spring potential energy:

[tex]PE_g=PE_s[/tex]

[tex]m.g.h=\frac{1}{2} \times k.\Delta x^2[/tex]

[tex]1.4\times 9.8\times 1.15=0.5\times 300\times \Delta x^2[/tex]

[tex]\Delta x =0.32433\ m= 324.33\ mm[/tex] is the compression in the spring

b)

When there is a constant air resistance force of 0.6 newton then the apparent weight of the body in the medium will be:

[tex]w'=m.g-0.6[/tex]

[tex]w'=1.4\times 9.8-0.6[/tex]

[tex]w'=1.01\ N[/tex]

Now the associated gravitational potential energy is converted into the spring potential energy:

[tex]PE_g'=PE_s[/tex]

[tex]w'.h=\frac{1}{2} \times k.\delta x^2[/tex]

[tex]1.01\times 1.15=0.5\times 300\times \delta x^2[/tex]

[tex]\delta x=0.087996\ m=87.996\ mm[/tex]

c)

On moon, as per given details:

[tex]m.g'.h=\frac{1}{2} \times k.\delta x^2[/tex]

[tex]1.4\times 1.63\times 1.15=0.5\times 300\times \delta x^2[/tex]

[tex]\delta x=0.13227\ m=132.27\ mm[/tex]