How has the Doppler effect and the redshift of stars and galaxies indicated that the universe is expanding?

What was the most difficult obstacle to overcome in the creation of an autonomous state after indian independence was achieved? a british willingness to go to war to retain the region b. religious differences between hindus and muslims c. ethnic differences between tribal regions d. indian princes' inability to decide on a format of government

Afootpath is to be constructed in a park in the shape of a parallelogram. when a coordinate plane is laid over a map of the park, the vertices of the footpath are (-4,2) (8,2) (11,7) and (-1,7). what is the perimeter of this path

The first atomic explosion was detonated in the desert north of alamogordo, new mexico, on july 16, 1945. what percentage of the strontium-90 ( yr) originally produced by that explosion still remains as of july 16, 2016?