What is the difference between Kinetic Energy and Speed?

Click For Summary

Discussion Overview

The discussion revolves around the difference between kinetic energy and speed, exploring their definitions and implications in physics. Participants express confusion about the concepts and their relationship, with a focus on understanding rather than deriving conclusions.

Discussion Character

  • Conceptual clarification, Debate/contested

Main Points Raised

  • Some participants assert that knowing the formulae does not equate to understanding the difference between kinetic energy and speed.
  • One participant defines speed as the distance traveled in unit time and describes kinetic energy as the ability to do work.
  • Another participant emphasizes that two objects can have the same speed but different kinetic energies, using the example of a pea and an express train to illustrate this point.
  • A participant notes that both projectiles (the pea and the express train) have the same kinetic energy per gram, raising questions about the essential differences between them.

Areas of Agreement / Disagreement

Participants express varying levels of understanding, with some agreeing that formulae alone do not clarify the concepts, while others highlight specific differences without reaching a consensus on the overall distinction.

Contextual Notes

There are limitations in the discussion regarding the assumptions made about the definitions of speed and kinetic energy, as well as the implications of their relationship in different contexts.

Shardul Khare
Messages
23
Reaction score
0
I know the formulae,but really don't understand the difference
 
Physics news on Phys.org
Shardul Khare said:
I know the formulae
That is the difference.
 
Speed the distance traveled in unit time.

KE is the ability to do work.

I'd rather be hit by an object with a lot of speed than one with a lot of energy.
 
  • Like
Likes   Reactions: sophiecentaur and anorlunda
Shardul Khare said:
I know the formulae,but really don't understand the difference
A pea and an express train may be traveling at the same 'speed' but you know which one has more KE. What is the essential difference between to two projectiles?
PS They both have the same Kinetic Energy per gram.
 

Similar threads

Undergrad How can we prove the kinetic energy equation
  • · Replies 2 ·
Replies
2
Views
2K
Undergrad Torque and Rotational Kinetic Energy Relationship
  • · Replies 4 ·
Replies
4
Views
2K
Undergrad How to calculate the kinetic energy of an object propelled by a magnet?
  • · Replies 15 ·
Replies
15
Views
1K
Undergrad Same old question, I still don't get it: E=1/2mv^2 - more E with V?
  • · Replies 41 ·
2
Replies
41
Views
4K
Undergrad Relationship between Concentration of a Force and Energy Density
  • · Replies 11 ·
Replies
11
Views
2K
High School Can energy be decomposed?
  • · Replies 2 ·
Replies
2
Views
1K
High School About verification on Kinetic energy and work
  • · Replies 16 ·
Replies
16
Views
3K
Undergrad Lost Energy from a Reciprocating Piston
  • · Replies 31 ·
2
Replies
31
Views
4K
Undergrad Question about Momentum vs. Kinetic Energy vs. Deforming In Collisions
  • · Replies 2 ·
Replies
2
Views
2K
High School The formulae for kinetic energy and Joules
  • · Replies 12 ·
Replies
12
Views
2K