Find Velocity of Two Moving Objects: Formula for Relative Speed Calculation

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SUMMARY

The discussion focuses on calculating the relative velocity of two moving objects, specifically cars with different speeds. The formula for relative velocity is defined as Relative V = V1 - V2. In the example provided, Car A moves at 30 m/s and Car B at 60 m/s, resulting in a relative velocity of 30 m/s when calculated as 60 m/s - 30 m/s. The discussion emphasizes the importance of considering the first object as stationary to simplify the calculation of relative motion.

PREREQUISITES
  • Understanding of basic physics concepts, particularly motion and velocity.
  • Familiarity with the formula for relative velocity.
  • Knowledge of speed measurement units, specifically meters per second (m/s).
  • Ability to perform basic arithmetic operations.
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  • Study the principles of relative motion in physics.
  • Learn about vector addition and subtraction in velocity calculations.
  • Explore real-world applications of relative velocity in automotive engineering.
  • Investigate the effects of acceleration on relative velocity between moving objects.
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Students of physics, automotive engineers, and anyone interested in understanding motion dynamics and relative speed calculations.

missie
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what formula can i use when i wanted to find out the velocity of two moving object?

like 2 car going foward on the same road but different speed. Car 1 in front is at 30m/s and car 2 in back is going 60m/s. how can i find the velocity of car b relative to car a?
 
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Let's say car A was moving at 30m/s and car B was also at moving at 30m/s, if they looked at each other they wouldn't be moving, so their relative velocity is 0.
But if a car C was moving at 60m/s both car A and B would agree it was moving at 30m/s.

So the formula is quite simple: relative V=V1-V2=60m/s-30m/s=30m/s.
Also V2-V1 doesn't equal -30m/s, it only means I think you're going at 30m/s in the other direction.

Always think of it as if the first variable was standing still.
 

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