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The velocity of a car changes from 10 m/s east to 30 m/s east in 4 seconds. What is the acceleration of the car?
A.
10 m/s2 east
B.
5 m/s2 east
C.
5 m/s2 west
D.
10 m/s2 west

Respuesta :

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Answer:

5 m/s² east

Explanation:

Acceleration is change in velocity over change in time. It can be expressed mathematically as:

[tex]\displaystyle{\vec a = \dfrac{\Delta \vec v}{\Delta t}}\\\\\displaystyle{\vec a = \dfrac{\vec v_2 - \vec v_1}{t_2-t_1}}[/tex]

Where [tex]\displaystyle{\vec v_2}[/tex] is final velocity, [tex]\displaystyle{\vec v_1}[/tex] is initial velocity, [tex]\displaystyle{t_2}[/tex] is final time and [tex]\displaystyle{t_1}[/tex] is initial time.

Therefore, from the problem, we know that:

  • final velocity is 30 m/s east.
  • initial velocity is 10 m/s east.
  • final time is 4 seconds.
  • initial time is 0 second.

Therefore:
[tex]\displaystyle{\vec a = \dfrac{30 \ \, \sf{m/s} \ \, east- 10 \ \, m/s \ \, east}{4 \ \, \sf{seconds}-0\ \, seconds}}\\\\\displaystyle{\vec a = \dfrac{20 \ \, \sf{m/s} \ \, east}{4 \ \, \sf{seconds}}}\\\\\displaystyle{\vec a = 5 \ \, \sf{m/s^2} \ \, \sf{east}}[/tex]

Therefore, acceleration will be 5 m/s² east.