Speed stay constant with velocity change?

[Red X]

Hey everyone, I have just started physics and have come upon a question asking if an object could have a constant speed and changing velocity, my guess is that this is incorrect because I would think that you would need to slow down to change direction, and with a constant speed the object would have to be deflected? I'm not sure, so if anyone could help explain this to me I would appreciate it.

 

Thanks

[Janus]

Circular motion is an example of a constantly changing velocity with a constant speed.

[CraigD]

Circular motion is an example of a constantly changing velocity with a constant speed.

Yes. More generally, any acceleration vector perpendicular (at a 90° angle, orthogonal) to a body’s velocity vector will change only the velocities direction, not its magnitude (speed).

 

Most of us have experience with changing velocity without changing speed, when we steer a car/bike without applying the brakes or accelerator/pedals.

[Jay-qu]

Velocity is a vector quantity, this means direction is included. While speed is only a scalar, size is all that speed is concerned about. So it is possible to have a constant speed (how fast something is going) while having a changing velocity (the direction is changing). As Janus said, circular motion is a good example of this. :)