Please give me thorough and clear explanation where i can read properly. I need it ASAP. For question #8 its a tricky one so please read carefully, thank you!

15.

A stationary horizontal disk of radius R and Mass M is dropped on top of a rotating disk of same radius R but of mass 2M spinning at a speed of wo, sharing same axis of rotation. What will the resulting rotational speed of be? Owy = 2wo OWE = 34 Ow = Owy = 7 WOIf a solid sphere, cylinder, and hoop are allowed to roll down an inclined plane from the same height. Given Moment of inertia of Solid cylinder MR2, of Solid sphere is = MR, and of hoop is MR2 O Not enough information, mass of the objects should be given. O All will reach the bottom at the same time. The cylinder will reach the bottom first. O Sphere will reach the bottom first. The hoop will reach the bottom first.A man of weight 80 Kg is standing in an elevator which is moving with a constant velocity of 6 m/s in downward direction. The apparent weight of a man will be (take g=10 m/s?) DON O 640 N O 1280 N O 320 N 800 NWhat is the cost of heating water in a swimming pool of radius 3.5m and depth 1.3 m from 13C to 27C, if the price of energy is $0.08/KWh. The specific heat of water is 4186 J/Kg/C and density of water is 1000Kg/m3. (Helpful Hint: Volume of cylinder is Trzh) O $95.50 O $133 O $65.15 O $30.25 O $15.15