## Jan_EE Group Title The Coefficient of kinetic friction between the tires of your car and the roadway is "μ". (a) If your initial speed is "v" and you lock your tires during breaking, how far do you skid? (b) What is the stopping distance for a truck with twice the mass of you car, assuming same initial speed and coefficient of kinetic friction. I'm stuck on (b), my mass cancels out every time, but that doesn't seem right one year ago one year ago

1. Shadowys Group Title

Your mass is supposed to cancel out. Note that the distance formulas do not have mass in them and that in the work-kinetic energy theorem, there is no other force except friction. Also: $$F_f = ma$$ $$\mu_s mg = ma$$ $$a=\mu_s g$$ Don't worry about it.:)

2. Jan_EE Group Title

Thanks alot. I solved a and i got (V^2)/19.6μ. Help me confirm is it is correct

3. Shadowys Group Title

Yup! :) That's the distance.

4. Jan_EE Group Title

thks a whole lot

5. Shadowys Group Title

You're welcome :)

6. Jan_EE Group Title

Pls helpppp i have another question. Do i just post it here or there is somewhere else i could post pls?

7. Shadowys Group Title

Close the question and post a new one. This way more people will take notice of it :)