MTEL Practice Test 2025 – Complete Exam Preparation

Acceleration refers to the rate at which an object's velocity changes over time. In physics, it is understood as both a vector quantity, which means it has both magnitude and direction, and an essential aspect of motion. When an object speeds up, slows down, or changes direction, it is experiencing acceleration.

For example, when a car speeds up from a standstill, its velocity increases, which reflects positive acceleration. Conversely, if the car is slowing down, it is still accelerating, just in a negative direction, often referred to as deceleration. This concept is crucial in understanding motion because it links to Newton’s laws, which describe how forces affect an object’s movement.

The other options do not accurately capture the definition of acceleration. The change in mass over time does not relate to motion and is not a standard concept in physics. The total force acting on an object refers to the net force, which can determine acceleration through Newton's second law of motion but is not a description of acceleration itself. Lastly, the measure of energy in a system pertains to concepts like kinetic or potential energy, which are distinct from acceleration. Thus, identifying acceleration as the change in velocity over time directly defines its significance in the study of motion.