What is the difference between a scalar and a vector?

A scalar is a value that has only a size (otherwise known as magnitude), not a direction. A scalar is unaffected by the direction in which the object concerned is travelling. Examples include kinetic energy, speed and distance. A vector on the otherhand, has both size and a direction. The direction in which the vector is facing affects the value of the vector, even taking a negative value if it's travelling in the opposite direction to what you take as positive! Examples include momentum, velocity and displacement.

ST

Related Physics A Level answers

All answers ▸

A piece of card is released from rest at a height of 0.5m above a light gate. It falls freely and a computer measures the velocity as it passes through the light gate to be 3.10m/s. What is the acceleration due to gravity measured by this experiment?


Two balls with the same kinetic energy have mass of ball a = m and ball b = 2m. What is the ratio of their momentums: a/b?


A stationary unstable neutral particle decays into 2 separate particles with equal mass and velocity, what might the resulting bubble chamber diagram look like?


Why does the rate of change of potential difference between two capacitor plates decrease as the capacitor discharges?