Determine spring constant for my RSA project and real absorber car by using Hooke's Law.

Week 9

For this week based on my adviser opinion I determine spring constant for my RSA project and real absorber by using Hook's Law

HOOKE LAW
Any physicist knows that if an object applies a force to a spring, then the spring applies an equal and opposite force to the object.
Hook’s law gives the force a spring exerts on an object attached to it with the following equation:

F = –kx
Where the minus sign shows that this force is in the opposite direction of the force that’s stretching or
compressing the spring. (k is called the spring constant, which measures how stiff and strong the spring is. x is the distance the spring is stretched or compressed away from its equilibrium or rest position.

RSA SPRING CONSTANT

For my RSA project I using mass of weight of iron (dumbbell) 6.75kg.In real life the acceleration of the gravity is  g = 9.81 m/s2

And the F is determining by mass time gravity of acceleration. How I determine the spring constant for my RSA spring:

Force at the maximum compression of 0.2 meters

F = mg = (6.75kg)(9.8 m/s2) = 66.15 N

Hook’s law says

F = –kx

Looking only at the magnitudes and therefore omitting the negative sign get

k=F/x
k=66.15N/0.2m=330.7N/m

 

This data are very important to make me analysis the project to  make the comparison to the real absorber car.From this data I can find out the input power based on spring constant, This input power I will explain more detail soon.Figure 1 is the weight and figure to how i using that weight to determine spring constant.

 

Figure 1

 

Figure 2

REAL CAR ABSORBER

I make some example comparison for the spring constant for the actual car that have a mass of 1,000 kilograms,

and have four shock absorbers, each 0.5 meters long determine how strong the spring can be Assuming that shock absorbers use springs,

Each one has to support a mass of at least 250 kilograms, which weighs the following:

F = mg = (250 kg) (9.8 m/s2) = 2,450 N

Where F equals force, m equals the mass of the object, and g equals the acceleration due to gravity, 9.8 meters per second2.

The spring in the shock absorber will, at a minimum, have 2,450 Newton of force at the maximum compression of 0.5 meters.

So the spring constant can be determine 

k=F/x
k=2,450N/0.5m=4900N/m

Figure 3=Real spring absorber car

 

Figure  3