Kinematics in 1 dimension - 2 objects interlinked, find time

AI Thread Summary
A race driver accelerates from rest at 5.5 m/s² after a pit stop, reaching a velocity of 22.55 m/s in 4.1 seconds. During this time, another car travels at a constant speed of 69.4 m/s, covering a distance of 284.54 meters. To determine when the entering car catches up, it's suggested to use a graph of position versus time for both cars. The discussion emphasizes the importance of visual aids and strategic problem-solving approaches for similar kinematics questions. Understanding these concepts can help clarify the solution process for catching up scenarios in physics.
googol
Messages
5
Reaction score
0
A race driver has made a pit stop to refuel. After refueling, he starts from rest and leaves the pit area with an acceleration whose magnitude is 5.5 m/s^2; after 4.1 seconds he enters the main speedway. At the same instant, another car on the speedway and traveling at a constant velocity of 69.4 m/s overtakes and passes the entering car. The entering car maintains its acceleration. How much time is required for the entering car to catch up with the other car?

Homework Equations


I DO NOT understand how do those type of questions. I had a lot of difficulty with this question and could not come up with the right answer. Along with helping me with this question, are there any specific strategies to go about solving these type of questions??

The Attempt at a Solution


After refueling, car #1
Vi= 0m/s
a= 5.5 m/s^2
t= 4.1 s
vf= ? Vf= vi + at
Vf = 0 + (5.5)(4.1)
vf = 22.55 m/s

____
Other car, car #2
V= 69.4 m/s
t= 4.1 s

deltax = vt + 1/2at^2
deltax = (69.4)(4.1) + 0
deltax = 284.54 m

and from here... I'm completely stuck.
Help, please!
 
Physics news on Phys.org
It helps to draw a diagram or graph of what is going on. I would recommend a graph showing x vs t of both vehicles for starters.
 
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