Question

energy transformation: pe - ke
if an object has 100 joules of potential energy (pe) at the top of a ramp, how much kinetic energy (ke) will there be at the other two locations indicated, half - way down the ramp and at the bottom the ramp?
a 0j and 50j
b 50j and 0j
c 50j and 100j
d 100j and 50j
in the first question, we described an energy transformation in a situation without friction. in reality, we almost always must contend with friction when analyzing energy transformations. how would the values change and why?

Explanation:

Step1: Apply conservation of mechanical energy

In the absence of friction, the total mechanical energy (sum of potential energy PE and kinetic energy KE) is conserved. At the top of the ramp, total mechanical energy $E = PE+KE=100 + 0=100\ J$.

Step2: Calculate KE at point B

At point B, $PE = 50\ J$. Since $E=PE + KE$ and $E = 100\ J$, then $KE=E - PE=100 - 50=50\ J$.

Step3: Calculate KE at point C

At the bottom of the ramp, $PE = 0\ J$. Since $E=PE + KE$ and $E = 100\ J$, then $KE=E - PE=100 - 0=100\ J$.

Answer:

C. 50J and 100J