An object of mass 1.5 kg does rotational motion. Its angular velocity is 30 rpm and the radius of circular path is 2 m. Find kinetic energy of the object. a) 4.71 J b) 2700 J                                                        c) 29.6 J

16. Kathy is changing the tire of her car on a steep hill 20.0 m high. She trips and drops the 10.0 kg spare tire, which rolls down the hill with initial speed of 2.00 m/s. what is the speed of the tire at the top of the next hill, which is 5.00 m high? (Ignore the effects of Rotational Kinetic Energy and friction.) *Use g=9.8   a. 18.8 m/s b. 17.3 m/s c. 12.56 m/s d. 14.6 m/s e. 16.43 m/s

Two solid spheres of radius R and mass m are initially separated by a distance d such that the two centres of mass are separated by d+3R as shown below. The spheres are initially at rest, but the gravitational force  accelerates them towards each other until they collide.a) Calculate the initial mechanical energy of the system.b) Calculate the gravitational potential energy of the system at the moment they collide.c) Derive an expression for v. State carefully what physical law you are applying.d) Show that, in the limit d >> R, the velocity v is independent of d.

Calculate the rotational inertia of a wheel that has a kinetic energy of 46.4 kJ when rotating at 267 rev/min. Number i Units