## Essential University Physics: Volume 1 (4th Edition) Clone

She will not burn of the calories she is claiming to burn off. It would take her $4.27 \times 10^4$ reps to burn off the chocolate bar.
We calculate how many reps she will need. We use unit conversions to find that the energy is equal to: $=230\times4184=9.6\times10^5 \ J$. Now, we see how many reps, which we will call x, are needed: $9.6\times10^5 \ J=(45)(.5)(x) \\ x = 4.27 \times 10^4$ This is much more than 5, so she will not burn of the calories she is claiming to burn off.