In uniform circular motion, the velocity of an object moving in a circle at a constant speed depends on the radius of the circle. When you decrease the radius in uniform circular motion while keeping the speed constant, the velocity of the object increases.
The velocity of an object in uniform circular motion can be calculated using the formula:
v = (2πr) / T
where v is the velocity, r is the radius of the circle, and T is the period of the motion (the time taken to complete one full revolution).
If you decrease the radius while keeping the speed constant, the period of the motion (T) remains the same because the time taken to complete one revolution doesn't change. However, since the radius (r) in the formula decreases, the velocity (v) increases. This means that the object has to travel a shorter distance in the same amount of time, resulting in a higher velocity.