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Astuntman jumping off a 20-m-high building is modeled by the equation h=20-5t^2, where t is the same in seconds. a high-speed camera is ready to film him between 15m and 10m above the ground. for which interval of time should the camera film him?

The radius of the earth is two times the radius of the moon. what fraction of the volume of the earth is the volume of the moon?

Ijust need these 2 questions answered (the second pic is just confirmation i'm not confident in that answer)