I think this might be a really simple question, but i'm not sure.
A car driving at a speed of 80km/h is going to rear-end a car moving at a speed of 60km/h. What is the maximum speed the first car can have just as it reaches the second car, to avoid a collision?
I think the answer is just 60km/h, but that's just my logical thinking. I don't think any of the equations for constant acceleration apply here, since I'm only given 2 velocities.
2006-07-19 09:51:49 · 11 answers · asked by darcy_t2e 3 in Science & Mathematics ➔ Physics
You are correct in thinking that 60 km/h is the maximum, just as long as that speed is achieved before the collision. However, while is does involve an acceleration (actually deceleration or reverse acceleration), that need not be constant. Any function of velocity that gets the trailing car to 60 km/h before collision is acceptable.
2006-07-19 11:35:59 · answer #1 · answered by Ѕємι~Мαđ ŠçїєŋŧιѕТ 6 · 0⤊ 0⤋
Assuming linear unlimited distance, the first car must travel at the same speed as the approaching car. Anything speed less or more will result in a collision eventually.
2006-07-19 09:58:47 · answer #2 · answered by Richard B 4 · 0⤊ 0⤋
60km/h has to be the answer. There can't be a collision at the same speed. It's just a tricky question because you have to understand that the maximum speed can be the only answer. 59km/h would be the wrong answer, because it's not the maximum..
2006-07-19 10:00:12 · answer #3 · answered by joeythekangar00 1 · 0⤊ 0⤋
Well, if the car were to speed up to around 186000 miles persecond and opena hyperspace window. It, contained in a the subspace bubble needed for FTL travel, would pass the car and avoid collision! It really was just a simple question, you just had to look deeper.
2006-07-19 10:15:09 · answer #4 · answered by rcktpilot 1 · 0⤊ 0⤋
I like your reasoning: 60 km/h works for me: We assume (although the problem as stated does not say) that we are permitted to apply braking in order to try to avoid the collision.
2006-07-19 09:56:28 · answer #5 · answered by Anonymous · 0⤊ 0⤋
It all depends on what the terms "first car " refering to. If it's the car going 80 km/hr, the assumption you're making, than you're answer is correct. However, if the "first car" is the car going 60 km/hr than the answer is 80 km/hr.
2006-07-19 11:08:29 · answer #6 · answered by Jatt 1 · 0⤊ 0⤋
its gonna collide no matter what so dont worry about it just make sure you have fresh batterys in your camera and a great spot to view from, then kick back and enjoy!
otherwise wouldnt you think it would be a speed less then 60?
2006-07-19 09:57:23 · answer #7 · answered by Anonymous · 0⤊ 0⤋
Any allowed speed is good when you pass the other car.
Bye bye!
2006-07-19 10:59:11 · answer #8 · answered by Thermo 6 · 0⤊ 0⤋
faster than 60 you collide , slower than 60 you dont reach 2nd car , thus .... 60
2006-07-19 09:59:46 · answer #9 · answered by gjmb1960 7 · 0⤊ 0⤋
I'm pretty sure you're right - 60kph. If you are traveling the same speed, you won't collide.
2006-07-19 09:56:25 · answer #10 · answered by bablunt 3 · 0⤊ 0⤋