Question

1.

In two to three sentences, in your own words, explain the statement:   "The Moon is constantly free-falling into the Earth".

2.  

A solid sphere, a solid disk, and a thin hoop are all released from rest at the top of the incline (h₀ = 20.0 cm).

a) Without doing any calculations, decide which object would be spinning the fastest when it gets to the bottom. Explain

b) Again, without doing any calculations, decide which object would get to the bottom first. Hint: which one has greater translational speed? Think CoE!

c) Assuming all objects are rolling without slipping, have a mass of 2.00 kg and a radius of 3.00 cm, find the rotational and translational speed at the bottom of the incline of any one of these three objects.

Answer 1

solution to when a other body The main is moving any body is in influence of gravitational force due to any then r is called as freely falling mation. around in its orbit around the Earth due to the gravitational fance between the moon and Earth. Therefore this can also be teamed as facely falling motion. All the potential energy will get conceited into kinetic anagy. the kinetic energy has two components ie rotational kinetic energy and translational kinetic energy- motion 2.

All the potential Rotational enegy Tansl. KE KE Now using teams of VEwr, the translational kinetic eneigy can be written in rotational kinetic enegy The body which will have bouest moment of ineitia will have largest to for a quien MandR because ngho is constant for all the bodies Thus w solid sphere W sold desc> we noob 6 Now using Valor Usoud spheu > V soud disc > Hool Thus soled sphere will reach the bottom fiest

с 5 llz FR2 For pure rolling V= wR ngho- Imut I w² For solid sphere I= 2 MR? Mgho= I mus+ 2x2 MREW? → Mgho= 7 MWARZ logho For Disc IT MR² » Mg ho=hmura x MP3 xw² = Muse? For Lool I = MR² » Mgho = 1 MP + 2 x mew? MRw? » w=/gho 10 112 2 ( 4415 gho R2 gho 1/2 R2 We are supposed to find for any one object Lets say For boob la 9.8) X 0.20 = 46670 eodlo (0-03)2 Using VEUR = 4670 X 0.03 = 1040 mls