Question

Is it possible that a force changes only in the direction of motion without any change in the speed of the object.​​​​ illustrate your answer with example.

Answer 1

Yes when an object is in a circular motion with uniform speed, there is an force called an centripetal force which acts towards the centre of the circular path traversed by object.
This force only changes the direction of velocity and it makes it tangentially so that object can revolve in a circular path
Example
Take a bucket half filled with water tie to a rope and rotate it vertically with a good speed
u will see that water doesn't fall down
(unless u slow down)