A car is moving with a uniform speed. However its momentum is changing. Then the car

Momentum is a vector quantity defined as the product of mass and velocity. While speed is a scalar representing magnitude, velocity is a vector that includes both magnitude and direction [2]. In uniform motion, if the speed remains constant but the momentum changes, it implies the direction of the velocity vector is changing. This occurs in curved paths, such as circular or elliptical motion, where the object is constantly changing its direction of travel. In uniform circular or elliptical motion, the object experiences centripetal acceleration because its velocity direction is not constant, even if its speed is. Therefore, a car with uniform speed but changing momentum must be moving on a non-straight path, such as an elliptical one, where the direction of motion is continuously altered.

Sources

1. [2] Science-Class VII . NCERT(Revised ed 2025) > Chapter 8: Measurement of Time and Motion > 8.4 Uniform and Non-uniform Linear Motion > p. 117