Which of the following is a vector?

CONCEPT:

• Speed: The rate of change of distance is called speed.
  • It is a scalar quantity.
• Velocity: The rate of change of displacement is called velocity. 
  • It is a vector quantity.
• Scalar quantities: The physical quantities which have only magnitude and no direction are called scalar quantities or scalars.
  • Examples: Mass, volume, density, time, temperature, electric current, Luminious intensity, speed, etc.
• Vector quantities: The physical quantities which have both magnitude and direction and obey the laws of vector addition are called vector quantities or vectors.
  • Examples Displacement, velocity, acceleration, force, momentum, Impulse, etc.

EXPLANATION:

1. Time is a scalar quantity.
2. Volume is a scalar quantity.
3. Speed is a scalar quantity.
4. Velocity is a vector quantity. So option 4 is correct.