The problem involves two identical objects moving at different speeds (5 m/s and 25 m/s) and asks for the ratio of their kinetic energies. The context is rooted in the principles of kinetic energy and motion.
Some participants have made progress in calculating the kinetic energies and are exploring the relationship between the kinetic energy ratio and the speed ratio. There is a mix of arithmetic attempts and conceptual clarifications, with some participants questioning the relevance of potential energy in this context.
Participants note the importance of considering the mass of the objects, which is the same for both, and some express confusion regarding the arithmetic needed to finalize the ratio. There is also mention of the need to square the velocities when discussing their ratios.
Hello chris.hart. Welcome to PF !chris.hart said:it reads, '' two identical objects move with speeds of 5m/s and 25m/s. what is the ratio of their kinetic energy
so i think i need to use the equation ke=1/2 mv^2
this is how far i got ke=12.5*m and ke=312.5*m
SammyS said:Hello chris.hart. Welcome to PF !
What is the ratio of those two numbers?
How does that ratio compare to the ratio of the two speeds?
I get that (312.5m)/(12.5m) = 25.0 .chris.hart said:i can't know what the ratio is without finishing the arithmetic? or am i missing something
chris.hart said:thanks guys but i figured out my problem.
id use the formula pe=ke which is the equivalent of mgh * .5mv^2
so i can just simply eliminate the mass on the both sides and solve the equation
Those velocities should be squared .lep11 said:Since the objects are identical they have the same mass Ek1/Ek2=½mv1/½mv2=v1/v2...
You're right.SammyS said:Those velocities should be squared .