[填空题]
A car starts rolling down* (q-,m in6n8evlt agdlt9ru / a 1-in-4 hill (1j3us hezkpg*/b ; 9rx-lwwm).-in-4 means that for each 4 m traveled along the road, the elevation change is 1 m). How fast wzmwl -px bk) ;h*rg.s/93e juis it going when it reaches the bottom after traveling 55 m? (a) Ignore friction.
(b) Assume an effective coefficient of friction equal to 0.10.
