Ke = (1/2) m v^2
is the kinetic energy of a mass m moving at speed v
This isn't so much a question, but a query:
What does this mean?
K.E. = 1/2 mv2
I can do the homework on my own if someone lets me know. Thanks.
2 answers
now as a simple example think of a mass m at rest. We push on it with a force F and it accelerates with a = F/m
The speed is
v = a t
The distance is
d = (1/2) a t^2
The work in is
F * d = m a d
If all is well and no energy is lost then the work in = the kinetic energy
but work in as we said is
m a d = m (1/2) a^2 t^2
but we know that v^2 = a^2 t^2
so
work in = (1/2)m v^2
so
Ke = (1/2) m v^2
The speed is
v = a t
The distance is
d = (1/2) a t^2
The work in is
F * d = m a d
If all is well and no energy is lost then the work in = the kinetic energy
but work in as we said is
m a d = m (1/2) a^2 t^2
but we know that v^2 = a^2 t^2
so
work in = (1/2)m v^2
so
Ke = (1/2) m v^2