Page 125 - 2023 PPIAC RMIC BOOK

LET'S DIVE IN- SINGLE CAR ACCIDENT
TIME & DISTANCE

GIVEN:
A CAR SKIDDED WITH ALL FOUR TIRES SLIDING ACROSS THREE LEVEL SURFACES BEFORE IT
STRUCK A UTILITY POLE AND STOPPED. THE FIRST SURFACE THE CAR SLID ACROSS WAS
PAVEMENT WITH A COEFFICIENT OF FRICTION OF 0.80. THE SECOND SURFACE WAS
GRAVEL WITH A COEFFICIENT OF FRICTION OF 0.55. THE LAST SURFACE THE CAR SLID OVER
WAS GRASS WITH A COEFFICIENT OF FRICTION OF 0.45. THE CAR SLID 102 FT ON THE
PAVEMENT, 43 FT ON THE GRAVEL, AND 22 FT ON THE GRASS BEFORE HITTING THE
UTILITY POLE AT 25 MPH. THE CAR DRIVER’S PERCEPTION-REACTION TIME WAS 1.5
SEC.
1. WHAT WAS THE VELOCITY OF THE CAR AT THE BEGINNING OF THE GRASS?.
2. WHAT WAS THE VELOCITY OF THE CAR AT THE BEGINNING OF THE GRAVEL?
3. WHAT WAS THE VELOCITY OF THE CAR AT THE BEGINNING OF THE SKID MARKS?
4. WHAT WAS THE TOTAL TIME THE CAR WAS SKIDDING PRIOR TO IMPACT?
5. HOW FAR WAS THE CAR FROM IMPACT AT THE BEGINNING OF THE DRIVER’S PERCEPTION
REACTION TIME?