How Fast is the Car When It Passes the Train?

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SUMMARY

The discussion focuses on calculating the speed of a car as it passes a train, with the train moving at a constant speed of 33 m/s and the car initially 32 m behind, traveling at 47 m/s and accelerating at 4 m/s². To determine the car's speed at the moment it passes the train, participants suggest using the displacement equations, specifically delta x = v₀t + 1/2at², and setting the displacements equal to find the time of intersection. The key to solving the problem lies in correctly formulating the initial equations for both the car and the train.

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  • Understanding of kinematic equations, specifically for uniformly accelerated motion.
  • Familiarity with concepts of relative motion and displacement.
  • Basic knowledge of algebra to manipulate equations.
  • Ability to solve quadratic equations to find time of intersection.
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  • Study kinematic equations for uniformly accelerated motion in detail.
  • Learn how to set up and solve problems involving relative motion.
  • Practice solving quadratic equations to determine time and velocity in motion problems.
  • Explore graphical methods for visualizing motion and displacement over time.
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Students studying physics, particularly those focusing on kinematics, as well as educators looking for examples of motion problems involving acceleration and relative speed.

AraProdieur
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1. Homework Statement
A train is moving parallel and adjacent to a highway with a constant speed of 33 m/s. Initially a car is 32 m behind the train, traveling in the same direction as the train at 47 m/s and accelerating at 4 m/s^2.
What is the speed of the car just as it passes the train? Answer in units of m/s.



2. Homework Equations
So far, I have thought of using delta x= volt+ 1/2at^2
I also think that I have to account for the displacement between the two trains, which is 14 m.
The thing that I don't understand is how to calculate something as it passes or catches up to another thing.

If there is any advice, thanks!
 
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Get the two equations for displacement/position in terms of time...

to find when they meet, set the two displacements equal... then you can get the velocity of the car at this time...

The main part is getting the two initial equations right...
 

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