Constant acceleration.
Explanation
The motion of a body under the influence of an external force is governed by Newton’s Second Law of Motion. This law establishes the quantitative relationship between force, mass, and acceleration, expressed mathematically as:
F = ma
Where:
- F = Net unbalanced force applied
- m = Mass of the body
- a = Acceleration produced
Analysis:
Rearranging the formula for acceleration gives a = F / m.
- The applied force (F) is constant.
- The mass (m) of the body is fixed.
- Since the ratio of force to mass remains unchanged, the resulting acceleration (a) must also remain constant.
Consequently, the body will continue to gain velocity at a uniform rate, meaning it moves with constant acceleration.
Evaluation of Incorrect Options:
- Constant velocity: This implies zero acceleration, which occurs only when the net force acting on the body is zero (Newton's First Law).
- Increasing or Decreasing acceleration: These scenarios would require the applied force to vary in magnitude or the mass of the body to change during motion.
Key Takeaway:
A constant unbalanced force acting on a fixed mass produces uniform (constant) acceleration. Velocity changes continuously, but the rate of change of velocity (acceleration) remains steady.