Answer:
a) v = 32.8 m/s
b) v= 15.4 m/s
Explanation:
a)
- Applying the definition of acceleration (assumed to be constant), we can write the following expression for the velocity v:
where v₀ is the initial velocity and a is the acceleration, being t the
time elapsed.
- In the case a) the acceleration and the velocity vectors have both the same direction (due north), so both have the same sign, which means that the car is speeding up.
- Replacing by the givens v₀ and t in (1), we get:
b)
- In this case, the acceleration vector and the velocity vector have opposite directions, so the car slows down, due to both vectors have opposite signs.
- Replacing by the givens in (1) and taking into account the signs, we get: