Un grúa cuyo rendimiento es del 50% está instalada a un motor cuyo rendimiento es del 80%. Si al motor se le
proporciona una potencia de 800watt, calcular la
velocidad constante con la cual podrá subir un bloque e
masa 1kg (g = 10m/s2)
Help me, please :(

Light from a sodium lamp passes through a diffraction grating that has 1000 slits per millimeter. the interference pattern is viewed on a screen 1.000 m behind the grating. the first (m = 1) two bright yellow fringes that are visible are 0.7288 m and 0.7300 m from the central maximum. what are the wavelengths of these two fringes?

2) why do satelites not fall while revolving around the earth?

Which phrase describes the paleo-indians of prehistoric arkansas? a. grew cornb. lived in cliff dwellings c. crafted beautiful potteryd. hunted with stone-tipped spearswhich phrase describes native arkansas from the woodland traditiona. developed widespread agricultureb. hunted mastodon and woolly mammothc.built rectangle-shaped homesd. traded salt with other groups