Acceleration involves a change in speed and change in direction.
Explanation;
Acceleration is the rate of change in velocity. It is calculated by dividing velocity with time and measured in m/s².
Acceleration is a vector quantity, which means it has both magnitude and direction. Since direction is the rate at which velocity of a body or object in motion changes, it means it has two components direction and speed.
Therefore, acceleration is the increase in speed, or decrease in speed , or changing in direction.
