A ball travels from north to south at 60km/h. After being hit by a bat, it travels from west to east at 60km/h. Is there a change in velocity?

Yes, there is a change in velocity.

Explanation:

The initial direction of travel for the ball is North to South.

The final direction of travel for the ball is West to East.

Although the Speed of the ball remains constant (60 km/h), the Velocity of the ball changes.

This is because Speed is a scalar quantity whereas Velocity is a vector quantity.

Thus, Velocity depends on direction. If the direction of travel changes, so does the velocity of an object.