Grade 12 HWK Help: Acceleration of Car A

  • Thread starter Thread starter matrix_anki
  • Start date Start date
  • Tags Tags
    Grade 12
AI Thread Summary
Car A accelerates from 100 km/hr to 130 km/hr in 4.5 seconds, and the user seeks help with part C of the homework question. Part C asks how far an oncoming car traveling at 110 km/hr must be from Car A when it begins its acceleration to avoid a collision. There is confusion about whether the oncoming car is accelerating and the specific meaning of the distance requirement. The interpretation suggests that the distance should ensure Car A can safely return to its lane without hitting the oncoming vehicle. Clarifying these points is crucial for solving the problem effectively.
matrix_anki
Messages
1
Reaction score
0
Hi guys,

I need some help with part C of the question. I've already done the other 2 parts and shall post my solution to parts a and b soon. But in the meantime if any1 can get me started with c...

Car A traveling at 100km/hr begins to accelerate in order to pass another car traveling at 100 km/hr. Car A accelerates until it reaches a velocity of 130 km/hr which takes 4.5 s.

a) What is the acceleration of car A?
b) At the end of Car A's acceleration, how far in front of the other car is it?
c) If an oncoming car is traveling at 110km/hr, how far would it have to be from car A when it begins its acceleration.
 
Physics news on Phys.org
I'm frankly not exactly sure I understand what part c is asking. Is the other car accelerating? What does it mean "how far does it have to be from car A?" How far does it have to be to do what? I don't understand the question.

- Warren
 
Chroot, my interpretation of C is this: car A is just able to get back to its correct side of the road without hitting the oncoming car.
Assuming that, how far from A must this oncoming car (going at a steady 110 km/hr) be at the time A starts accelerating.
 
I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
Thread 'A cylinder connected to a hanging mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
Back
Top