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a car of mass 850kg hits a crash barrier at a speed of 30m/s . the car stops in 0.4s.calculate the force of the car.​

User Cbrauchli
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1 Answer

19 votes
19 votes

Given :-

  • Mass of Car = 850 kg
  • initial speed,u = 30 m/s
  • Time span in which car stop = 0.4 s

To Find :-

  • force on car

Solution:-

During the collision an impulse is created which due to which is equal to change in momentum.

Mathematically,


\green{ \underline { \boxed{ \sf{Impulse, F* t = m (v-u) }}}}

where

  • F = force
  • t = time span
  • m = mass
  • v= final speed
  • u = initial speed

Now,


\begin{gathered}\\\implies\quad \sf F * 0.4 = 850 * (0-30) \\\end{gathered}


\begin{gathered}\\\implies\quad \sf F * 0.4 = 850 * -30 \\\end{gathered}


\begin{gathered}\\\implies\quad \sf F = -(25500)/(0.4) \\\end{gathered}


\begin{gathered}\\\implies\quad \sf F = -63750 N \\\end{gathered}


\quad\quad\quad\quad\quad\quad(-ve sign denotes opposite direction)

Therefore, a force of 63750 Newton will act on the car in opposite direction.

User JonathanK
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