Physics, asked by arifnabila57, 6 hours ago

A car slows down to 80 m/s in 5 sec. Its retardation is found to be 2 m/s^2. calculate it's initial velocity​

Answers

Answered by Anonymous
5

Provided that:

  • Final velocity = 80 m/s
  • Time taken = 5 seconds
  • Acceleration = -2 m/s

Don't be confused! Acceleration cames in negative because it is given that there is retardation founded in the car as it slows down and we also know that retardation is the inverse of acceleration and acceleration is positive.

Solution: What about the initial velocity of the given car!?

  • The initial velocity of the given car = 90 metre per second

Using concept: First equation of motion

Using formula:

  • {\small{\underline{\boxed{\pmb{\sf{v \: = u \: + at}}}}}}

Where, v denotes final velocity, u denotes initial velocity, t denotes time taken and a denotes acceleration!!!!

Required solution:

:\implies \sf v \: = u \: + at \\ \\ :\implies \sf 80 = u + (-2)(5) \\ \\ :\implies \sf 80 = u + (-10) \\ \\ :\implies \sf 80 = u - 10 \\ \\ :\implies \sf 80 + 10 = u \\ \\ :\implies \sf 90 = u \\ \\ :\implies \sf u \: = 90 \: ms^{-1} \\ \\ :\implies \sf Initial \: velocity \: = 90 \: ms^{-1}

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