# Physics

posted by .

A 1125 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?

• Physics -

Can't figure it out. Does it have something to do with finding w?
w=2pi/T = square root of k/m but I don't have K or T?

• Physics -

Use the information provided to get the natural (and resonant) frequency of the suspension system with a total mass of M = 1205 kg. From that you can derive the spring constant, k.

f = [1/(2 pi)] sqrt(k/M)

The natural frequency will be the rate at which the car goes over washboard bumps at the resonant (maximum amplitude) condition.

When the people get out, the car body will rise by an amount
(80 kg)(9.8 m/s^2)/k

• Physics -

Thank you!

## Similar Questions

1. ### physics

A 1175 kg car carrying four 82 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 24 …
2. ### physics

I tried doing this problem but couldn't get the right answer. I don't get how the answer is 2.19cm. Is the distance referring to the vertical or horizontal distance Four people, each with a mass of 73.5 kg, are in a car with a mass …
3. ### physics

Four people, each with a mass of 72.7 kg, are in a car with a mass of 1110 kg. An earthquake strikes. The driver manages to pull of the road and stop, as the vertical oscillations of the ground surface make the car bounce up and down …
4. ### PHYSICS HELP!

A compact car has a mass of 1400kg. Assume that the car has one spring on each wheel, that the springs are identical, and that the mass is equally distributed over the four springs. What is the spring constant of each spring if the …
5. ### Physics

A compact car has a mass of 1400kg. Assume that the car has one spring on each wheel, that the springs are identical, and that the mass is equally distributed over the four springs. What is the spring constant of each spring if the …
6. ### Physics

The body of a 1269 kg car is supported on a frame by four springs. The spring constant of a single spring is 2.75 × 10 4 N/m. Four people riding in the car have a combined mass of 256 kg. When driven over a pothole in the road, the …
7. ### physics

A compact car has a mass of 1150 kg. Assume that the car has one spring on each wheel, that the springs are identical, and that the mass is equally distributed over the four springs. (a) What is the spring constant of each spring if …
8. ### physics

Your car rides on springs, so it will have a natural frequency of oscillation. (Figure 1) shows data for the amplitude of motion of a car driven at different frequencies. The car is driven at 24mph over a washboard road with bumps …
9. ### physics

The body of a 1285 kg car is supported on a frame by four springs. The spring constant of a single spring is 2.80 × 104 N/m. Four people riding in the car have a combined mass of 275 kg. When driven over a pothole in the road, the …
10. ### Physics

A car with a total mass of 1800kg (including passengers) is driving down a washboard road with bumps spaced 5.0m apart. The ride is roughest—that is, the car bounces up and down with the maximum amplitude—when the car is traveling …

More Similar Questions