Respuesta :

Speed. It is used in the equation force = mass X acceleration
AL2006

"Acceleration" is any change in speed or direction of motion ...
slowing down, speeding up, or curving away from a straight line.

You and I, and all other students of Physics, must re-educate
people.  We have to tell everyone that 'acceleration' does NOT
mean 'speeding up'.  AND, it doesn't even necessarily mean
any change in speed.