Which of the ff quantities is avector? A. KE B. Momentum C. speed D.work

The correct answer is B. Momentum.

Momentum is defined as the product of an object's mass and its velocity. Since velocity is a vector quantity (having both magnitude and direction), momentum is also a vector quantity.

$$\vec{p} = m\vec{v}$$

In contrast:

• Kinetic energy (KE) is a scalar quantity, representing the energy of motion.
• Speed is a scalar quantity, representing the magnitude of velocity.
• Work is a scalar quantity, representing the energy transferred by a force.