A weightlifter manages to lift a 133 kg (that's 293 pounds, which sounds much more impressive) weight a distance of 1.4 m. How many kcal of heat energy is equivalent to this lift?
To calculate the amount of heat energy equivalent to lifting a weight, we need to use the concept of work and conversion factors. The formula to calculate work is:
Work = Force * Distance
In this case, the force exerted can be found by converting the weight from pounds to Newtons using the conversion factor:
1 pound = 4.45 Newtons (approximately)
So, the converted weight becomes:
293 pounds * 4.45 N/pound = 1303.85 N (approximately)
Now, we can calculate the work done using the formula mentioned above:
Work = Force * Distance
= 1303.85 N * 1.4 m
= 1824.39 N∙m or Joules (J)
Since we need to calculate the energy in kilocalories (kcal), we convert Joules to kilocalories using the conversion factor:
1 kilocalorie = 4184 Joules (approximately)
So, the energy equivalent is:
1824.39 J * (1 kcal / 4184 J) = 0.44 kcal (approximately)
Therefore, lifting the weight is equivalent to approximately 0.44 kcal of heat energy.