physics
posted by johnny .
An automobile can be considered to be mounted on four identical springs as far as vertical oscillations are concerned. The springs of a certain car are adjusted so that the oscillations have a frequency of 3 Hz.
(a) What is the spring constant of each spring if the mass of the car is 1400 kg and the weight is evenly distributed over the springs?
N/m
(b) What will be the vibration frequency if five passengers, averaging 71.0 kg each, ride in the car with an even distribution of mass?
Hz

physics 
bobpursley
I will be happy to critique your thinking.

physics 
Christiaan
f = sqrt(k/m)
where f is the frequency, k is the spring constant of the four springs, and m is the mass of the car.
=> k = f²*m = (3 Hz)²*1400 kg =12600 N/m
This results is the results for the total of the four springs, so for one spring we divide the answer by four:
k/4 = 3150 N/m
The extra weight on the car will amount to 355 kg, bringing the total of car and passengers to 1750 kg.
=> f = sqrt(k/m) = sqrt(12600 (N/m)/17150 kg) = 2.68 Hz 
physics 
johnny
b) k =mw^2, k = 1400 * 18.84^2, k = 496924/4 = 124231 N/M

physics 
Anonymous
Christiaan your answer for the spring constant is wrong

physics 
Anonymous
not clear enough you have to demostrate all calculation

physics 
Kara
for a)you must first calculate the angular frequency,w, you are only given the frequency,f. to do that you use the equation:
w=2*pi*f
=2*pi*3Hz
next you take that and put it into the equation with k being the spring constant,w being the angular velocity, and m being the mass:
w= sqrt( k / m )
6*pi= sqrt( k / 1400)
...but since there are 4 springs you need to modify the equation to be:
6*pi= sqrt( 4k / 1400)
so the answer should be 124357.0155
Respond to this Question
Similar Questions

Physics SHM
An automobile can be considered to be mounted on four identical springs as far as vertical oscillations are concerned. The springs of a certain car are adjusted so that the oscillations have a frequency of 4 Hz. (a) What is the spring … 
physics
A glider on an air track is connected by springs to either end of the track. Both springs have the same spring constant,k , and the glider has mass M. A)Determine the frequency of the oscillation, assuming no damping, if k= 125N/m … 
physic
An airtrack glider attached to a spring oscillates between the 3.00 cm mark and the 50.0 cm mark on the track. The glider completes 10.0 oscillations in 36.0 s. What is the period of the oscillations? 
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 … 
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 … 
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 … 
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 … 
physics
The shock absorbers in the suspension system of a car are in such bad shape that they have no effect on the behavior of the springs attached to the axles. Each of the identical springs attached to the front axle supports 351 kg. A … 
physics
The shock absorbers in the suspension system of a car are in such bad shape that they have no effect on the behavior of the springs attached to the axles. Each of the identical springs attached to the front axle supports 351 kg. A … 
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 …