1kg of fat is equal to 30MJ of energy.the efficiceny of converting fat to energy is 20%. suppose you life a mass of 12kg 2.0m vertically,500 times, how much work do you do?
if all the energy used to do the work comes from the burning fat how much fat is used ?
Work =500mgh=500•12•9.8•2=117600 J.
You need 117600•100/20 =588000 J
1 kg gives 30•10⁶J,
mass of burning fat is
588000/30•10⁶ = 0.0196 kg
To calculate the work done, we can use the formula: work = force x distance.
1. Work done lifting a mass of 12kg vertically, 2.0m each time = 12kg x 9.8m/s^2 x 2.0m = 235.2J
Since the work is done 500 times:
2. Total work done = 235.2J x 500 = 117,600J
Now, let's calculate the amount of fat used in the conversion to energy:
3. Efficiency of converting fat to energy = 20%
4. Total energy used = Total work done / Efficiency = 117,600J / 0.20 = 588,000J
Using the given conversion rate:
5. 30MJ of energy equals 1kg of fat
Converting the total energy used from joules to megajoules:
6. Total energy used = 588,000J / 1,000,000 = 0.588MJ
Now, let's calculate the amount of fat used:
7. Fat used = Total energy used / Conversion rate = 0.588MJ / 30MJ = 0.0196kg
Therefore, approximately 0.0196kg (or 19.6g) of fat is used to lift the mass 500 times.
To calculate the work done, we can use the formula:
Work = Force x Distance x Number of Repetitions
In this case, the mass being lifted is 12kg, and it is lifted vertically for a distance of 2.0m, repeated 500 times. To find the force, we can use the formula:
Force = mass x acceleration due to gravity
The acceleration due to gravity is typically approximated as 9.8m/s^2.
So, Force = 12kg x 9.8m/s^2 = 117.6N
Now we can calculate the work done:
Work = 117.6N x 2.0m x 500 = 117,600 Joules
Now, let's calculate the amount of fat used to produce this energy. We know that 1kg of fat is equal to 30MJ (30 x 10^6 Joules) of energy, and the efficiency of converting fat to energy is 20% (0.20).
First, we need to convert the work done from Joules (J) to Megajoules (MJ):
Work (in MJ) = Work (in J) / (1,000,000)
Work (in MJ) = 117,600 J / 1,000,000 = 0.1176 MJ
Since the efficiency of converting fat to energy is 20% (0.20), we can find the amount of fat used as follows:
Fat Used (in MJ) = Work (in MJ) / Efficiency
Fat Used (in MJ) = 0.1176 MJ / 0.20 = 0.588 MJ
Finally, we can convert the fat used from Megajoules (MJ) to kilograms (kg):
Fat Used (in kg) = Fat Used (in MJ) / (30 x 10^6)
Fat Used (in kg) = 0.588 MJ / (30 x 10^6) = 0.0000196 kg (approximately)
Therefore, approximately 0.0000196 kg (or 0.0196 grams) of fat would be used to produce the energy required to perform the given work.