A roller coaster car is at the lowest point on its circular track. The radius of curvature is 22 m. The apparent weight of one of the passengers in the roller coaster car is 3 times her true weight. Determine the speed of the roller coaster.

Ozone layer in the upper atmosphere filters most of the harmful radiations of shorter wavelength. It actually absorbs the hazardous radiations like ultraviolet, gamma rays, x- rays and most of all those having shorter wavelength then the visible light. That's how the earth's atmosphere protects life on earth. But unfortunately, climate change and global warming is causing the depletion of ozone layer which is causing skin related diseases and harming not only the human life but also the plants and animals.