Where Does the Energy Come From for Motion Without External Forces?

In summary, when no external force is applied on a body, it will continue its motion without the need for additional energy due to Newton's first law. The body's initial velocity is what provides the kinetic energy for its motion. External forces would be required to change the motion or the kinetic energy.
  • #1
Cromptu
33
0
Forgive me if I'm missing a basic concept,

A body does have a natural tendency to move, but a body does need energy to move! Where does this energy come from when no external force is applied on it?

Please help, I've been pondering over this doubt since a week..
 
Science news on Phys.org
  • #2
Cromptu said:
A body does have a natural tendency to move, but a body does need energy to move!
It does not need additional energy to continue moving, but a moving body certainly has kinetic energy.
Where does this energy come from when no external force is applied on it?
If no external forces act on a body, it will continue its motion without the need for additional energy.
 
  • #3
So,the kinetic energy comes from it's initial velocity..?
 
  • #4
Cromptu said:
So,the kinetic energy comes from it's initial velocity..?
Sure.

Newton's first law just says that if there are no external forces acting, then the body continues its motion at the same speed (and thus kinetic energy) in the same direction.

External forces would be required to change the motion or the kinetic energy.
 
  • #5
Thankyou :)
 

Related to Where Does the Energy Come From for Motion Without External Forces?

What is Newton's First Law of Motion?

Newton's First Law of Motion, also known as the law of inertia, states that an object at rest will stay at rest, and an object in motion will stay in motion with a constant velocity, unless acted upon by an external force.

What is the significance of Newton's First Law of Motion?

This law is important because it helps us understand the concept of inertia, which is the tendency of an object to resist changes in its state of motion. It also serves as the basis for the other two laws of motion.

Can you give an example of Newton's First Law of Motion?

One example is a soccer ball sitting still on a field. It will not start moving on its own unless someone kicks it or an external force, such as wind, pushes it.

How does Newton's First Law of Motion relate to everyday life?

This law is applicable in many everyday situations, such as when a car comes to a stop when the brakes are applied, or when a book falls off a table and comes to rest on the floor. It explains why objects and people tend to keep moving until acted upon by an external force.

What is the difference between Newton's First Law of Motion and the law of inertia?

Newton's First Law of Motion and the law of inertia are often used interchangeably, but technically the law of inertia is a more general concept that applies to all objects, while Newton's First Law specifically deals with the behavior of objects in motion. However, both essentially state the same idea that objects will remain in their current state unless acted upon by an external force.

Similar threads

Newton's first law and a body on an infinite and frictionless road
    • Thermodynamics
Replies
16
Views
994
Newton's first law of motion and Inertial Systems
    • Thermodynamics
Replies
2
Views
1K
I Magnetic fields are exceptions to the second law of thermodynamics?
    • Thermodynamics
Replies
2
Views
1K
Does Newton's or Galileo's first law depend on gravity?
    • Thermodynamics
Replies
4
Views
1K
I Spring balance analysis from a system point of view
    • Classical Physics
Replies
24
Views
834
I Extending Newton's laws -- Is the concept of force still defined?
    • Mechanics
2
Replies
35
Views
3K
Newton's First Law problem -- Conceptual question about KE
    • Thermodynamics
Replies
7
Views
2K
First law of thermodynamics, mass/energy in the Universe
    • Thermodynamics
Replies
2
Views
2K
Is Newton's Second Law Flawed? An Exploration of Zero Force in Space
    • Thermodynamics
Replies
14
Views
7K
A Average temperature in a greenhouse
    • Thermodynamics
Replies
2
Views
1K

Hot Threads

Recent Insights

Back
Top