g A 4 lb weight stretches a spring 2 ft in equilibrium. It is attached to a damping mechanism with constant c. (a) Find the value of c for which the motion is critically damped. (b) If the motion is critically damped, find the displacement y(t) when the spring is initially displaced 6 inches above equilibrium and given a downward velocity of 3 ft/sec.

Solution :

Given :

Weight = 4 lb

Stretched of a spring in  equilibrium,Δ = 2 ft

a). We know that

F = kΔ

4 = k x 2

k = 2 lb/ft

∴ Stiffness of the spring is, k = 2 lb/ft

Motion is critically damped.

C = 0.99729 lb.s/ft.

b). Displacement

Initial displacement = 6 inches

Therefore, displacement :

u can delete ur account.

1. go on google and write

2 open this and click on your profile pic and if your profile is not appearing, then u have to log in.

3. when u click on your profile pic, there appears four options on the top.

4. click on the 1st option and scroll down and go at the bottom.

5. click on edit profile.

6. there appears a option 'prefernces' and at that option at the right side , 'edit' is written.

7. click on the edit option.

8. there is a option " i want to delete my account" and click on that.

hope this u

and ur welcm

: )