A disk, with a radius of 0.25 m, is to be rotated like a merry-go-round through 1000 rad, starting from rest, gaining angular speed at the constant rate through the first 500 rad and then losing angular speed at the constant rate until it is again at rest. The magnitude of the centripetal acceleration of any portion of the disk is not to exceed 400 m/s².
(a) What is the least time required for the rotation?
(b) What is the corresponding value of α₁?

Alow cost, low earth orbit (leo) satellite is to be fabricated at a university, for subsequent launch by rocket. what are the constraints and objectives for selection of a material suitable for the satellite bus (i. e. the structure)? explain each in brief. (15 marks) b)suggest sources of data which could support the selection of materials for applications in space. (5 marks) c) set weights for the objectives listed in (2a) using the digital logic method. (5 marks)

A10.0 kg cart and a 15kg cart are locked together with a compressed spring between them. they are then released so that the spring pushes the two carts apart. the 10.0 kg cart is moving at 4.5 m/s afterward. how fast is the 15kg cart moving? 3.0 m/s 2.0 m/s 4.5 m/s 5.0 m/s

Asun-sized star will spend most of its lifetime as a: white dwarf red giant protostar main-sequence star