Which of the following does not change when a car keeps a constant speed, but changes direction?
a.Acceleration
b.Velocity
c.Momentum
d.Mass***
Can someone review my answer and make sure that I'm right?
All of those vector things change in either magnitude or direction. The only scalar is mass, so you are right.
You could argue about centripetal acceleration because if the radius is constant the centripetal acceleration has constant MAGNITUDE, but the direction is not constant which is why it happened in the first place :)
To determine if your answer is correct, let's review the options and their definitions.
a) Acceleration is the rate of change of velocity. It relates to how quickly the car's speed and/or direction changes. If a car is changing direction, it is experiencing a non-zero acceleration.
b) Velocity is a vector quantity that includes both speed and direction. When a car changes direction while maintaining a constant speed, the velocity changes because direction is part of the vector.
c) Momentum is the product of an object's mass and velocity. When the car changes direction, its velocity changes, so its momentum also changes.
d) Mass is a scalar quantity that measures the amount of matter in an object. It does not change when a car keeps a constant speed but changes direction.
Based on this, your answer (d. Mass) is correct. Mass does not change when a car maintains a constant speed but changes direction.