Question

Three cars (call them A, B, and C) are moving with the same speed but in dierent

directions. Car A has the most mass and Car C has the least mass. Suddenly, all three drivers

slam on their brakes and the cars skid to a stop. If the coecient of friction between the tires

and the road is the same for all cars, which car skids the longest till it stops?

A. Car A

B. Car B

C. Car C

D. They all travel the same distance

Answer 1

$s=v_0^2/(2a)$

$F=ma\to \mu m_1g=m_1a\to a_1=\mu g$

$F=ma\to \mu m_2g=m_2a\to a_2=\mu g$

$F=ma\to \mu m_3g=m_3a\to a_3=\mu g$

$a_1=a_2=a_3=a$ and $s_1=s_2=s_3=s$

D. They all travel the same distance