A cyclist traveling on a bicycle at a rate of 5ft/s is approaching an intersection. When the cyclist is 50m away from the intersection, a car traveling at a rate of 30ft/s crosses the intersection. The bicycle and the car are on roads that are at right angles with each other. How fast is are the bicycle and the car separating 2 seconds after the truck leaves the intersection?
2007-01-30 23:10:28 · 5 answers · asked by Anonymous in Science & Mathematics ➔ Physics
The term "crosses" does not define the position of the car. If the position of the car at that instant can be defined, it is simple in concept to move them 2 seconds at their respective speeds. Determine relative position, break down the vector of their speeds into the part heading directly away from the other and the (remainder) of the speed, and then add the two numbers. Without exact positioning I can't supply numbers, maybe the thought helps.
2007-01-30 23:31:06 · answer #1 · answered by hasse_john 7 · 1⤊ 0⤋
I think hasse_john's idea is about the best you are going to get . It's probably the one with the least number of assumptions that lets you get some sort of answer to a fundamentally pointless question.
Assume the car is on the back of the truck, that the roads stay straight for as long as you like, that the truck and bike do not change their astonishingly slow speeds then the bike is 50metres-10ft south of the intersection and heading north at 5ft/second when the truck+car are 60ft west and heading west at 30ft/sec.
After you've done the drawing and calculated the vector magnitude of the relative velocity express it in perches per bell to tick off the examiner as much as he/she has aggravated you.
2007-01-31 09:27:29 · answer #2 · answered by Anonymous · 0⤊ 0⤋
Does this question take into consideration the stopping time for both the car and the bike...and where did the truck come in?
My answer is if an unknow truck was stopped in the intersection, two seconds after the car and bike entered...they would not be traveling at any speed. Cryptic question.
NI
2007-01-31 07:20:17 · answer #3 · answered by NITA E 2 · 0⤊ 0⤋
Well, well, your question is mixing me, since you speak about feet per second and the bike is 50 meters from the intersection. How fast are the bike and car separating 2 seconds after .. what truck ?? leaves the intersection? 2 seconds maybe, since you ask "how fast" eh!
2007-01-31 07:20:31 · answer #4 · answered by gabnella 6 · 0⤊ 0⤋
i can only solve this problem if you tell me from what angel you sow all this,at what distance you where standing when i drive the truck away from the intersection.
2007-01-31 07:19:32 · answer #5 · answered by toploser 5 · 0⤊ 0⤋