Un proyectil que pesa 80 kgf es lanzado verticalmente hacia arriba con una velocidad inicial de 95 m/s. Se desea saber:
a) ¿Qué energía cinética tendrá al cabo de 7 s?
b) ¿Qué energía potencial tendrá al alcanzar su altura máxima?
6) ¿Qué energía cinética alcanzará un cuerpo que pesa 38 N a los 30 s de caída libre?
7) ¿Qué energía cinética alcanzará un cuerpo de masa 350 kg si posee una velocidad de 40 m/s?
8) ¿Con qué energía tocará tierra un cuerpo que pesa 2500 g si cae libremente desde 12 m de
altura?

People with normal vision cannot focus their eyes underwater if they aren't wearing a face mask or goggles and there is water in contact with their eyes. in a simplified model of the human eye, the aqueous and vitreous humors and the lens all have a refractive index of 1.40, and all the refraction occurs at the cornea, whose vertex is 2.60 cm from the retina.with the simplified model of the eye, what corrective lens (specified by focal length as measured in air) would be needed to enable a person underwater to focus an infinitely distant object? (be careful-the focal length of a lens underwater is not the same as in air! assume that the corrective lens has a refractive index of 1.62 and that the lens is used in eyeglasses, not goggles, so there is water on both sides of the lens. assume that the eyeglasses are 2.05cm in front of the eye.)