Apply conservation of angular momentum:
L = Iw = const.
L = angular momentum, I = moment of inertia, w = angular velocity, L must stay constant.
L must stay the same before and after the professor brings the dumbbells closer to himself.
His initial angular velocity is 2π radians divided by 2.0 seconds, or π rad/s. His initial moment of inertia is 3.0kg•m^2
His final moment of inertia is 2.2kg•m^2.
Calculate the initial angular velocity:
L = 3.0π
Final angular velocity:
L = 2.2w
Set the initial and final angular momentum equal to each other and solve for the final angular velocity w:
3.0π = 2.2w
w = 1.4π rad/s
The rotational energy is given by:
KE = 0.5Iw^2
Initial rotational energy:
KE = 0.5(3.0)(π)^2 = 14.8J
Final rotational energy:
KE = 0.5(2.2)(1.4)^2 = 21.3J
There is an increase in rotational energy. Where did this energy come from? It came from changing the moment of inertia. The professor had to exert a radially inward force to pull in the dumbbells, doing work that increases his rotational energy.
If you increase the number of trials in an experiment it will make the test more valid and legitimate.As you take the same test/experiment once or twice you could see if your results are similar to each other.
Hydrogen is a gas and the first element listed on the periodic table.Elemental hydrogen has three naturally occurring isotopes they are namely protium, deuterium and tritium. Protium is the most common isotope with an occurrence of 99.98 percent. This isotope consists of one proton and one electron.
Efficiency of heat engine is determined by the ratio of difference in temperature of cold from hot reservoir to the temperature of hot reservoir over temperature of hot reservoir.
Answer: Option A
<u>Explanation:</u>
Efficiency is defined as the output from the input. So it is the ratio of energy output to the energy input. In case of temperature, it is the change in temperature from hot reservoir to cold reservoir with the overall hot reservoir temperature.
Thus, option A is the most suitable as the heat will be transferred from high temperature to low temperature. So the hot reservoir will be releasing the energy. So the conversion of hot reservoir temperature to cool reservoir temperature is defined as the efficiency. Thus, option A is the most suitable.
The weight on Earth would be:
77.3 * 9.8
= 757.54 Newtons
1 Newton = 0.2248 lbf
757.54 * 0.2248
= 170.29 lbf
On the asteroid:
77.3 * 0.08
= 6.18 Newtons
Applying the same conversion:
77.3 * 0.2240
= 17.31 lbf
