* Speed is the magnitude of velocity. It tells us how fast an object is moving, regardless of direction.
* Velocity is a vector quantity, meaning it has both magnitude (speed) and direction.
If a particle has zero speed, it means it's not moving at all. Since it's not moving, it can't have a direction of motion. Therefore, its velocity must also be zero.
In simpler terms:
Imagine a car parked on the side of the road. Its speed is zero because it's not moving. Since it's not moving, it doesn't have a direction either. So, its velocity is also zero.
Important Note: While a particle can have zero speed and non-zero acceleration (for example, at the peak of its trajectory in projectile motion), it cannot have zero speed and non-zero velocity in straight line motion.
