Calculate Initial Velocities & Determine Fault: Skid Data Analysis"

[123bob123]

Homework Statement

A H2 was headed North and a convertible Mini Cooper was headed East. Due to faulty traffic signals, they collided, leaving a skid mark 7.6 m long at an angle of 51 degrees North of East. What was the initial velocity of each vehicle and, if the speed limit was 30 mph, who should get a ticket

Using the above skid data, what would the intitial velocities and who should get the ticket if the East-bound car was a Smart Car and the North-bound car was the convertible Mini?

Had to toss out the rest of the template as I really am in the dark. Seems really simple but I can't for the life of me recall how to attack this.

 

[tiny-tim]

Hi 123bob123!

(i assume the question gives you masses, and the coefficient of fricyion?)

Momentum is always conserved in collisions, so use conservation of momentum (and find the final velocity from the stopping distance and the standard constant acceleration equations).

What do you get? ​

 

[123bob123]

According to the problem itself, it doesn't give the mass for the vehicles or the coefficient which is what is throwing me for a loop. Is there any way to do this?

 

[k33g0rz]

mass of H2 > then mass of Mini coop

assume same tires same road so friction coeff is the same

 

[123bob123]

Do you mind running me through the problem or a similar example? As I'm not entirely sure how I would be to make assumptions without the actual numbers.

 

[tiny-tim]

Hi 123bob123!

According to the problem itself, it doesn't give the mass for the vehicles or the coefficient which is what is throwing me for a loop. Is there any way to do this?

No. You need at least to know the coefficient of friction, and the approximate ratio of masses of the two vehicles.

(do they expect you to look them up? )

 

[123bob123]

I really doubt that is the case. Must've been a mistake.