Is momentum a vector quantity? if yes what determines its direction?
The Correct Answer and Explanation is:
Yes momentum is a vector quantity. Its direction is determined by the direction of the object’s velocity.
Momentum is defined as the product of an object’s mass and its velocity. Mathematically it is expressed as:
p = m × v
Where p is momentum, m is mass, and v is velocity. Since velocity is a vector quantity, which means it has both magnitude and direction, and mass is a scalar quantity (it only has magnitude), the momentum takes its direction directly from the velocity. This makes momentum a vector quantity because any vector multiplied by a scalar remains a vector in the same direction.
To understand this better consider a car moving north with a certain speed. The car has mass and it is moving with velocity toward the north. Therefore its momentum also points to the north. If the same car were moving south with the same speed its momentum would point to the south. This directional quality is what makes momentum different from a scalar quantity like energy or speed.
Momentum plays a crucial role in physics especially in the laws of motion and conservation principles. For instance in a closed system where no external forces act the total momentum before and after a collision remains the same. This principle is known as the conservation of momentum. In such cases it is very important to consider the direction of momentum vectors when analyzing the system. If two objects collide and move in opposite directions their momenta might partially or completely cancel out depending on their masses and velocities.
Because momentum has direction it is often represented using arrows in diagrams to show how the motion of an object or system changes over time. Understanding the vector nature of momentum is essential in solving problems related to collisions, motion, and forces in both classical and modern physics.
