Explaining Work: No Change in Energy Despite Force Applied

Click For Summary
SUMMARY

The discussion clarifies that when a force of 100N is applied to a box experiencing an equal frictional force of 100N, the net force is zero, resulting in no change in kinetic or gravitational potential energy. This scenario illustrates that while work is defined as the change in energy, no work is done on the box as it maintains constant velocity. The energy expended in overcoming friction is converted into heat rather than contributing to the box's motion. Understanding this principle is crucial for grasping the concept of work in physics.

PREREQUISITES
  • Newton's First Law of Motion
  • Concept of Net Force
  • Understanding of Kinetic and Gravitational Potential Energy
  • Basic Thermodynamics (Energy Conversion to Heat)
NEXT STEPS
  • Study the implications of Newton's First Law in real-world scenarios
  • Explore the concept of work-energy theorem in physics
  • Learn about friction and its effects on motion
  • Investigate energy conversion processes, particularly in mechanical systems
USEFUL FOR

Students of physics, educators explaining mechanics, and anyone interested in the principles of energy and motion in physical systems.

Fusilli_Jerry89
Messages
158
Reaction score
0
Can someone please explain to me how work is the change in energy, yet if you are applying a force of 100N to a box, and 100N of friction is making the net force zero, how is work being done when the box is already in motion, yet there is no change in kinetic of gravitational potential energy?
 
Physics news on Phys.org
Work is often a difficult concept to wrap your mind around, but extremely useful in most cases. From Newton's first law we could determine that without external forces, the box once given a shove would remain at that velocity for all eternity. That it requires a constant force to maintain velocity, implies that there is a force operating against its motion. The energy ends up as heat.
 

Similar threads

  • · Replies 8 ·
Replies
8
Views
2K
Replies
29
Views
3K
  • · Replies 5 ·
Replies
5
Views
2K
Replies
1
Views
2K
  • · Replies 58 ·
2
Replies
58
Views
3K
Replies
25
Views
3K
Replies
15
Views
2K
  • · Replies 16 ·
Replies
16
Views
1K
  • · Replies 12 ·
Replies
12
Views
3K
Replies
17
Views
2K