The discussion focuses on calculating the final velocity of a 4kg block subjected to a tension of 35N while being lowered 10m from an initial velocity of 5m/s. The correct approach involves determining the net force (Fnet) and using the work-energy principle, where work done equals the change in kinetic energy (KE). The participant raises a question regarding the potential energy (PE) component in the equation W = PE + KE, highlighting the importance of distinguishing between conservative and non-conservative forces in energy calculations.
PREREQUISITESStudents in physics, particularly those studying mechanics, as well as educators looking to clarify concepts related to energy conservation and the work-energy principle.
jisun.hong said:Homework Statement
You have a 4kg block attached to a string with T=35N. If the block begins at 5m/s and is lowered 10m what is approxaimate final velocity of block?
So I got the question right:
Find Fnet and times it by 10m and set (Fnet)(10)= work = KE and find velocity from KE.
But my question is W= PE + KE so where is the PE?
Thanks for the help.
The net work done by all forces is the change in KEjisun.hong said:Homework Statement
You have a 4kg block attached to a string with T=35N. If the block begins at 5m/s and is lowered 10m what is approxaimate final velocity of block?
So I got the question right:
Find Fnet and times it by 10m and set (Fnet)(10)= work = KE and find velocity from KE.
The work done by non-conservarive forces is the change in (KE +PE). You should carefully note the differences between the 2 equations. The latter incorporates the work done by gravity or other conservative forces in the PE term.But my question is W= PE + KE so where is the PE?
Thanks for the help.