A 1175 kg car carrying four 80 kg people travels over a rough "washboard" dirt road with corrugations 4.0 m apart which causes the car to bounce on its spring suspension. The car bounces with maximum amplitude when its speed is 17 km/h. The car now stops, and the four people get out. By how much does the car body rise on its suspension owing to this decrease in weight?(adsbygoogle = window.adsbygoogle || []).push({});

I first tried figuring the natural frequency of the car:

[tex]\omega_o=(2\pi\upsilon)/(\Delta(x))=(2\pi(17km/h)(1hr/60s)/(.004km)[/tex] This gives 445.059 rad/s.

I then tried to figure out k:

[tex]\kappa=(m1+m2)\omega_o^2=((1175 kg+(4*180kg))(445.059rad/s)^2[/tex] This gives 3.75e8.

Finally, I tried finding [tex]\Delta(x)=\Delta(F)/\kappa=(m_2*g)/(\kappa)=((180 kg*4)(9.8m/s^2))/(3.75*10^8)[/tex]This gives 1.8e-5 m, or .00188 cm, this is wrong, where did I go wrong? Help!

PS This is the first time I use Latex so if it looks odd I'm sorry!

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Oscillations Car carrying four people find how much body rises

**Physics Forums | Science Articles, Homework Help, Discussion**