contestada

A car that was traveling east slows (without turning) for 4 seconds, to a final speed of 40 m/s. 367 10 m/s east 12 m/s east 28 m/s east 44 m/s east 47 m/s east 52 m/s east A If the magnitude of its acceleration was 3 m/s2, what was its initial velocity?​

Respuesta :

sqdancefan

Answer:

  (d)  52 m/s

Step-by-step explanation:

You want the initial velocity of a car traveling in a straight line that decelerates for 4 seconds at -3 m/s² to a velocity of 40 m/s east.

Velocity

Under uniform acceleration, the velocity is described by ...

  v₁ = v₀ +at

Here, we want v₀ such that v₁ = 40 m/s, a = -3 m/s², t = 4 s.

  40 = v₀ -3(4)

  52 = v₀ . . . . . . add 12

The initial velocity was 52 m/s east, choice D.