Question

A car speeds up and accelerates for 5.1 seconds at a rate of 2.2 m/s2. if the car's initial velocity was 9.3 m/s, what was the car's final velocity

after accelerating?
-9.7m/s
-11.2m/s
1.9m/s
20.5m/s

Answer 1

Recall the definition of average acceleration:

a = (v - u)/∆t

where u and v are the initial and final velocities, respectively.

So we have

2.2 m/s² = (v - 9.3 m/s) / (5.1 s)

v - 9.3 m/s = (2.2 m/s²) * (5.1 s)

v = 9.3 m/s + (2.2 m/s²) * (5.1 s)

v = 20.52 m/s ≈ 21 m/s