ashley7094
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An object has a mass of 60 kg. It decelerates from 50 m/s to 20 m/s when a resultant force of 300 N acts on it. For how long does the force act?
A 0.071 s
B 0.17 s
C 6.0 s
D 14 s​

Respuesta :

  • Force=300N
  • Mass=60kg

Find Acceleration

[tex]\\ \rm\longmapsto F=ma[/tex]

[tex]\\ \rm\longmapsto a=\dfrac{F}{m}[/tex]

[tex]\\ \rm\longmapsto a=\dfrac{-300}{60}[/tex]

[tex]\\ \rm\longmapsto a=-5m/s^2[/tex]

Now

  • u=50m/s
  • v=20m/s

Using 1st equation of kinematics

[tex]\\ \rm\longmapsto v=u+at[/tex]

[tex]\\ \rm\longmapsto t=\dfrac{v-u}{a}[/tex]

[tex]\\ \rm\longmapsto t=\dfrac{20-50}{-5}[/tex]

[tex]\\ \rm\longmapsto t=\dfrac{-30}{-5}[/tex]

[tex]\\ \rm\longmapsto t=6[/tex]

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