Suppose that a car weighing 2000 pounds is supported by four shock absorbers Each shock absorber has a spring constant of 6250 lbs/foot, so the effective spring constant for the system of 4 shock absorbers is 25000 lbs/foot. 1. Assume no damping and determine the period of oscillation of the vertical motion of the car. Hint: g 32 f/sec2 T314 2. After 10 seconds the car body is 1 foot above its equilibrium position and at the high point in its cycle. What were the initial seconds. conditions? 2 0.4871 ft, and yt y(o,-0100X 0.487 ft. and y(0)- X ft/sec. 3. Now assume that oil is added to each the four shock absorbers so that, together, they produce an effective damping force of - 6.93 Ib-sec/ft times the vertical velocity of the car body. Find the displacement y(t) from equilibrium if y(0)-0 ft and y(0)--10 ft/sec. y(t)

Respuesta :

Answer:

1).[tex]T=0.314sec[/tex]

2).[tex]y'(t)=21.24ft/s[/tex]

3).[tex]y(t)=10*sin(16.66*t)[/tex]

Explanation:

1.

Time of the oscillation of the vertical motion of the car is

[tex]T=2*\pi *\sqrt{\frac{m}{K}}[/tex]

[tex]T=2*\pi *\sqrt{\frac{2000}{25000*32}} =2\pi *0.05[/tex]

[tex]T=0.314sec[/tex]

2.

After 10 sec the car is at the high point of it's

[tex]y(0)=1.0 ft[/tex]

[tex]y(t)=-A*cos(wt)[/tex]

[tex]y'(t)=A*w*sin(wt)[/tex]

[tex]w=\frac{2\pi}{T}=16.66rad/s[/tex]

[tex]y'(t)=62.05*sin(20.0181)[/tex]

[tex]y'(t)=21.24ft/s[/tex]

3.

Coefficient r'

[tex]r=\frac{6.93}{2*m}[/tex]

[tex]r=0.0554[/tex]

[tex]w'=\sqrt{w_o^2-r^2}=\sqrt{16.67^2-0.5544^2}[/tex]

[tex]W'=16.66sec^{-1}[/tex]

[tex]y(0)=0[/tex]

[tex]y(t)=A*sin(w't)[/tex]

[tex]y(t)=10*sin(16.66*t)[/tex]