Final answer:
Using the formula from Newton's Second Law of Motion, F = ma, we can determine the net external force on a 78.0 kg sprinter accelerating at 1.40 m/s² is approximately 109.2 Newtons.
Step-by-step explanation:
The subject at hand deals with some essential principles of Physics, primarily focussing on the concept of Newton's Second Law of Motion. This law states that the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass. Mathematically speaking, it is expressed as F = ma, where F represents force, m is mass, and a stands for acceleration.
Applying the formula to the question's situation, our 78.0 kg sprinter begins the race with an acceleration of 1.40 m/s², meaning we will need to multiply these two values to get the net external force. Thus, the math comes out: F = 78.0 kg * 1.40 m/s² = 109.2 N. Enough to get an Olympic sprinter off the line!
So, we can conclude that the net external force exerted on the sprinter is approximately 109.2 Newtons. It should be noted, however, that in addition to the force of his own acceleration, many other elements can impact a runner's performance, like his particular running stride, the condition of the track, air resistance, and so on.
Learn more about Newton's Second Law of Motion