a model train moving at a constant speed around a circular track has a constant velocity?
False!
To determine whether a model train moving at a constant speed around a circular track has a constant velocity, we first need to understand the difference between speed and velocity.
Speed refers to the rate at which an object covers a distance, and it is a scalar quantity. It is calculated by dividing the total distance traveled by the time taken.
Velocity, on the other hand, is a vector quantity that includes both speed and direction. It tells us the rate of change of displacement of an object over time. Velocity is calculated by dividing the change in displacement by the time taken.
In the case of a model train moving at a constant speed around a circular track, we can conclude that its speed remains constant, as it covers the same distance in the same amount of time for every lap.
However, since the train is moving in a circular path, its direction is continuously changing. Therefore, its displacement is not constant, and consequently, its velocity is not constant.
When an object moves in a circular path at a constant speed, its velocity is always changing because the velocity vector is tangent to the circular path at any given point. Thus, the direction of velocity changes continuously, even though the speed remains constant.
In summary, a model train moving at a constant speed around a circular track does not have a constant velocity due to the continuously changing direction.