Question 578624: Hello i have a question in physics and need a little help. The problem say's "Four identical springs used as part of a car suspension system, one on each wheel. The spring compress by 6cm when the weight of the 1900kg car is applied to them.
a) What is the spring constant of each of the springs?
formula F=-kx I know f force which i believe is 1900kg car, x(displacement), and k is what im trying to find. Can you tell me if my formulas is correct. k=f/x
Answer by KMST(5328)   (Show Source):
You can put this solution on YOUR website! In physics they write the formula as F=-kx to show that the force the spring exerts on the car is in the opposite direction (up) to the car displacement (down, compressing the springs).
We do not need the minus sign here, because we do not need to specify direction. We know very well which way is up.
I would assume that the problem does not mean that the car was set down on each spring separately, doing four separate tests. They must have put the car down so it would be supported on all four springs, and each of the four springs compressed by 6 cm. That would mean that each spring is supporting one fourth of the weight of the car. (By happy coincidence, the center of mass of the car must have been at exactly the same distance from all four springs, so they all exerted the same force, and compressed by the same distance).
Also, since they gave you the mass in kg, and the distance in cm, they must want the spring constant in Newton/meter, so you will have to calculate weight (mass times acceleration of gravity, mg) in Newtons using g=9.8 m/s^2.
I would expect
mg=(1900kg)(9.8m/s^2)=19620 Newtons
F=19620/2 N = 4655 N
x=0.06m (6cm) and
k=(6455 Newton)/(0.06m)=  N/m
|
|
|
