A small car weighing 3,350 lbs is traveling due north when it collides with a pi
ID: 2259971 • Letter: A
Question
A small car weighing 3,350 lbs is traveling due north when it collides with a pick-up truck weighing 12,764 lbs which was traveling due east. After the collision the two vehicles move off together at an angle of 22o north of east. The driver of the car claimed that the truck driver was at fault because he was exceeding the speed limit going 79 mph.
If this were true, what was the car's initial velocity?
It was determined from skid marks that the velocity of the combined system was 31 mph just after the collision. What was the actual velocity of the car?
What was the actual velocity of the truck?
Please DO NOT list out answers, I know them. Practice problems. Just need explanations and conclusions to the right answers
Explanation / Answer
the velocity of combined mass =31 mph along 22 degrees north of east
==> final momentum along north direction=(3350+12764)*31*sin(22)=187128 lb-m/h
and final momentum along east direction=(3350+12764)*31*cos(22)=463159.85 lb-m/h
==> initial momentum along north direction =3350*v1
and initial momentum along east direction =12764*v2
by momentum balance
3350*v1=187128 lb-m/h
12764*v2 = 463159.85 lb-m/h
==> v1=velocity of car=55.86 mi/hr
==> v2=velocity of truck =36.28 mi/hr