Please help, Express kinetic energy in terms of m and p?

Click For Summary
SUMMARY

The discussion focuses on expressing kinetic energy (T) in terms of mass (m) and momentum (p). The user starts with the definitions of momentum (p = mv) and kinetic energy (T = (1/2)mv²). Through manipulation of these equations, the user arrives at the expression T = (p²)/(2m), confirming that kinetic energy can be expressed using momentum and mass. This derivation clarifies the relationship between kinetic energy and momentum in classical mechanics.

PREREQUISITES
  • Understanding of classical mechanics concepts, specifically kinetic energy and momentum.
  • Familiarity with algebraic manipulation of equations.
  • Knowledge of the relationship between mass, velocity, and momentum.
  • Basic calculus concepts, particularly derivatives, for understanding velocity as dx/dt.
NEXT STEPS
  • Study the derivation of kinetic energy from first principles in classical mechanics.
  • Learn about the conservation of momentum and its applications in physics.
  • Explore advanced topics in mechanics, such as relativistic momentum and energy.
  • Investigate the implications of kinetic energy and momentum in real-world scenarios, such as collisions.
USEFUL FOR

Students of physics, educators teaching classical mechanics, and anyone interested in the mathematical relationships between mass, velocity, and energy.

belleamie
Messages
24
Reaction score
0
Hi, I think my brain froze and I'm not seeing it
the problem is

the momentum is defined as
p=mv=m(dx/dt)
express the kinetic energy in terms of m and p

~ Now I know kinetic = T= (1/2)mv^2
and that P=mv
I figured that it must be t= (1/2)p^2
till i realized that I'm missing in terms of m. I just got stumped
 
Physics news on Phys.org
T= (1/2)p^2

You know p=mv, so p^2 gives (mv)^2

T=/= (1/2)(mv)^2

where =/= represents 'is not equal to'

I suspect that you will kick yourself when it dawns on you.
 
p=mv -> v=p/m

T=1/2*m*v^2

T=1/2*m(p/m)^2 -> T=1/2((p^2)/m)
 

Similar threads

Replies
5
Views
1K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 13 ·
Replies
13
Views
1K
Replies
7
Views
3K
Replies
2
Views
943
  • · Replies 19 ·
Replies
19
Views
2K
  • · Replies 8 ·
Replies
8
Views
1K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 12 ·
Replies
12
Views
3K