If the magnitude of the acceleration of a propeller blade's tip exceeds a certain value amax, the blade tip will fracture. if the propeller has radius r, is initially at rest, and has angular acceleration of magnitude α, at what angular speed ω will the blade tip fracture?

i think it would be 80 km/h because 30 + 50 = 80 (sorry if this not the right answer i'm trying my best)

the arctic is a region of the planet, north of the arctic circle, and includes the arctic ocean, greenland, baffin island, other smaller northern islands, and the far northern parts of europe, russia (siberia), alaska and canada.