What is the time taken for these 2 cars to meet?

  • Thread starter Thread starter nyrychvantel
  • Start date Start date
  • Tags Tags
    Cars Time
AI Thread Summary
Two cars, P and Q, start 1400 meters apart, with P traveling at a constant speed of 15 m/s and Q accelerating from rest at 5 m/s². To find the time taken for them to meet, one can set up equations for their positions over time and equate them. Car P's position is given by S = vt, while Car Q's position can be calculated using S = ut + 0.5at², with adjustments for direction. The discussion emphasizes the importance of using kinematic equations rather than graphical methods to solve the problem efficiently. The solution involves calculating the distance each car travels before they meet.
nyrychvantel
Messages
14
Reaction score
0

Homework Statement



Two cars, P and Q, are 1400m apart.
P is traveling at 15 ms-1, Q is accelerating from rest at 5.0 ms-2
They are traveling opposite direction(i.e. they are facing each other), what is the time taken for them to meet?
Also, what is the distance traveled by each car before meeting each other?

Homework Equations



a = \frac{v-u}{t}


The Attempt at a Solution



I got a = 5t, but it did not seem to help much...
Do I have to draw a graph for this question?
 
Physics news on Phys.org
nyrychvantel said:

Homework Statement



Two cars, P and Q, are 1400m apart.
P is traveling at 15 ms-1, Q is accelerating from rest at 5.0 ms-2
They are traveling opposite direction(i.e. they are facing each other), what is the time taken for them to meet?
Also, what is the distance traveled by each car before meeting each other?

Homework Equations



a = \frac{v-u}{t}


The Attempt at a Solution



I got a = 5t, but it did not seem to help much...
Do I have to draw a graph for this question?

No, just write out the position dependence over time for the two cars and equate. Assume Car 1 to b at x=0 and the second car to be at x=1400
Use
S=u*t+0.5*a*t*t (for the accelerated motion) (Use negative sign for acceleration)
S=v*t (for the constant velocity motion)
 
Thank you!
I forgot I can use area under a V-T graph of constant acceleration (and sub v=at) to get the total distance traveled by car Q.
 
Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Back
Top