Question:

Perhaps you can help me bring the first question further - In uniform
circular motion the acceleration is perpendicular to the velocity at every
instant, even though both change continulously in direction. Is there any
other motion having this property, or is uniform circular unique?

Thanks again-

Gail

Answer:

The fact that velocity and acceleration remain perpendicular only defines
uniform circular motion as long as the magnitude of the acceleration is
precisely v^2/r. Any other acceleration will result in departure from
circularity.

Regards,

JDJ