Can I use an accelerometer to measure the velocity of a car in a curve?
I found out the answer to the question in the following article SenSpeed: Sensing Driving Conditions to Estimate Vehicle Speed in Urban Environments
According to the article

When a vehicle makes a turn, it experiences a centripetal force, which
is related to its speed, angular speed and turning radius. Thus, by
utilizing the accelerometer and the gyroscope, we can derive the
tangential speed of a vehicle.

Therefore, just with the accelerometer is not possible to measure the velocity when an object is making a turn, it is necessary a gyroscope also.
The equation to measure the tangential velocity is:
v = Rω (1),
Where v is the tangential speed, R the radius of the curve and ω the angular speed.
As the centripetal acceleration is given by a = ω²R (2), reformulating (2) and substituting in (1), it is obtained:
v = a/ω (3).
Both a and ω are given by the accelerometer and the gyroscope respectively.