Two automobiles of equal mass approach an intersection. One vehicle is traveling
ID: 1294116 • Letter: T
Question
Two automobiles of equal mass approach an intersection. One vehicle is traveling with speed of 13.0 m/s toward the east, and the other vehicle is traveling north with speed v2i. Neither driver sees the other. The vehicles collide in the intersection and stick together, leaving parallel skid marks at an angle of 55.0 degrees north of east. The speed limit for both roads is 35 mi/h, and the driver of the northward-moving vehicle claims he was within the speed limit when the collision occurred. Is he telling truth? Explain your reasoning.
Explanation / Answer
FROM LAW OF CONSERVATION OF MOMENTUM
ALONG y -axis
m*V2i = (m+m)*V*sin 55....
V2i = 2*V*sin(55)...(1)
along X-axis..
m*13 = (m+m)*V*cos(55)....
13 = 2*V*cos(55).....(2)
dividing (1) and (2)..
(1)/(2) = tan (55) = V2i/13...
V2i = 13*tan(55) = 18.56 m/s = 41.72mi/h which is greater than speed limit 35mi/h..
he is not telling truth