Cuando el estudiante mantiene extendidos sus brazos horizontalmente, los objetos distan a 1.0 m respecto al eje de rotación y éste gira con una rapidez angular de 0.75 rad/s; el momento de inercia del estudiante y la silla, tienen y una magnitud constante de 3 kg .m². Suponiendo que el estudiante jalará los objetos horizontalmente a 0.30 m del eje de rotación, determinar: a) La nueva rapidez angular del estudiante. b) La energía cinética del estudiante antes y después de que los objetos sean aproximados al eje de rotación

Clothing made of several thin layers of fabric with trapped air in between, often called ski clothing, is commonly used in cold climates because it is light, fashionable, and a very effective thermal insulator. so it is no surprise that such clothing has largely replaced thickand heavy old-fashioned coats. (a) consider a jacket made of five layers of 0.1-mm-thick synthetic fabric (k = 0.13 w/m·°c) with 1.5-mm-thick air space (k = 0.026 w/m·°c) between the layers. assuming the inner surface temperature of the jacket to be 28°c and the surface area to be 1.25 m2, determine the rate of heat loss through the jacket when the temperature of the outdoors is 0°c and the heat transfer coefficient at the outer surface is 25 w/m2·°c. (b) what would your response be if the jacket is made of a single layer of 0.5-mm-thick synthetic fabric? what should be the thickness of a wool fabric (k = 0.035 w/m·°c) if the person is to achieve the same level of thermal comfort wearing a thick wool coat instead of a five-layer ski jacket?

If the radius of curvature of the cornea is 0.75 cm when the eye is focusing on an object 36.0 cm from the cornea vertex and the indexes of refraction are as described before, what is the distance from the cornea vertex to the retina? express your answer to two significant

What is friction? how does it affect the motion of an object?