contestada

A mobile starts with a speed of 250m / s and begins to decelerate at a rate of 3m / s². How fast is it after 45s?

Respuesta :

[tex] \large{ \underline{ \underline{ \bf{ \purple{Given}}}}}[/tex]

  • Speed of the mobile = 250 m/s
  • It starts decelerating at a rate of 3 m/s²
  • Time travelled = 45s

[tex] \large{ \underline{ \underline{ \bf{ \green{To \: find}}}}}[/tex]

  • Velocity of mobile after 45 seconds

[tex] \large{ \underline{ \underline{ \red{ \bf{Now, \: What \: to \: do?}}}}}[/tex]

We can solve the above question using the three equations of motion which are:-

  • v = u + at
  • s = ut + 1/2 at²
  • v² = u² + 2as

So, Here a is acceleration of the body, u is the initial velocity, v is the final velocity, t is the time taken and s is the displacement of the body.

[tex] \large{ \bf{ \underline{ \underline{ \orange{Solution:}}}}}[/tex]

We are provided with,

  • u = 250 m/s
  • a = -3 m/s²
  • t = 45 s

By using 1st equation of motion,

⇛ v = u + at

⇛ v = 250 + (-3)45

⇛ v = 250 - 135 m/s

⇛ v = 115 m/s

Final velocity of mobile = 115 m/s

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