Is There Any Net Force Acting on an Athlete Moving at Constant Velocity?

[bionut]

An athlete (mass of 50 kg) is moving with a constant velocity of 5ms. Determine the resultant force acting on him.

If it's a constant velocity he is not acclerating? Therefore a = 0 m/s/s; F=ma F=50 X 0 = 0N?

But there has to be a force dosent there? Would the force be equal to the mass affcted by gravity f=mg = 50 490.5N or is it 0N?

 

[cepheid]

But there has to be a force dosent there?

Why?

 

[bionut]

So if he's moving at a constant velocity --- he's not accerating therefore threre is no force affecting his velocity?

 

[cepheid]

So if he's moving at a constant velocity --- he's not accerating therefore threre is no force affecting his velocity?

No NET force, yes. Meaning all the forces that are acting on him (if any) must cancel each other out. That's Newton's second law. No net force means no acceleration.

 

[rwisz]

I can provide some clarification on the concepts of acceleration and force in this scenario. First, it is important to understand that acceleration is defined as a change in velocity over time. If an object is moving at a constant velocity, it means that its speed and direction are not changing, and therefore there is no acceleration. In this case, the athlete is moving at a constant velocity of 5 m/s, so we can say that his acceleration is 0 m/s^2.

Now, let's talk about the resultant force acting on the athlete. According to Newton's second law of motion, the resultant force on an object is equal to its mass multiplied by its acceleration. In this case, since the acceleration is 0 m/s^2, the resultant force on the athlete is also 0N. This means that there is no net force acting on the athlete, and he will continue to move at a constant velocity of 5 m/s.

However, it is worth noting that there are other forces acting on the athlete, such as the force of gravity. The force of gravity is always present and pulling objects towards the center of the Earth. In this case, the athlete's weight (which is equal to his mass multiplied by the acceleration due to gravity, g=9.8 m/s^2) is 490.5N. This means that there is a downward force of 490.5N acting on the athlete, but since he is not accelerating, the net force is still 0N.

In conclusion, while the athlete is moving at a constant velocity, there is no acceleration and therefore no resultant force acting on him. However, there are other forces at play, such as the force of gravity, which do not affect his constant velocity.