A Braking System with Spikes for Cars

[Alateo]

Homework Statement

After creating an emergency braking system that would deflate a set of tires to halt a car (Toyota Vios), an attempt to calculate for the following was made:

kinetic energy of the moving car,
time until deceleration,
distance traveled until rest,
force required to be applied on the brake pedal to trigger mechanism for deceleration,
normal and frictional force exerted on the tire by brake pads and vv,
and the inelastic collision of the spikes with the tires and the momentum conserved.

Relevant Equations

KE=1/2mv^2
a=(vf-vi)/t
d=((vf+vi)/2)t
sumF=0

Attached to the post is a file with an attempt at a solution.

The braking system is said to be a center-pull clamping system, which when activated by a brake lever (which equates to 355kN of force applied), triggers a tension force in the cables then clamps together two brake pads with spikes attached to deflate the tires. The only successful calculation made was that of kinetic energy; the rest are a lost cause due to a lack of a starting point.

Any guidance in the right direction to finding the correct calculations is greatly appreciated.

 

[pbuk]

How much of this paper were you given as the problem and how much have you written yourself?

The reason I ask is because much of the paper doesn't make sense. For instance:

The friction generated by the spikes on the tires is greater than the tires’ ability to rotate, thus halting the vehicle to a stop

The purpose of the spikes is to deflate the tyres; once they have done this they are no longer relevant. Once the tyres are deflated the car will slow down due to the much increased rolling resistance of a deflated tyre.

Having said that, in question 2 you are using a speed of 170 km/h and a acceleration of 1.2 x 9.8 m/s/s. Do you think this will work?

 

[Alateo]

With regards to the elementary error on unit conversion, the mistake has been fixed, thank you so much. I was wondering why my values looked wrong.

Much of the paper, including the rationale and car specifications, was given to us. We were simply asked to identify the possible concepts that could be applied and calculate those enumerated above in the "homework statement". Much apologies if the paper does not make sense. I do realize my mistake with regards to the deflated tire, and this has been corrected as well.

 

[berkeman]

Thread is closed for Moderation.

 

[berkeman]

Thread will remain closed for now. @Alateo -- Please check your PMs and respond to my questions about this thread. Thank you.