Bajo la acción del viento una puerta gira un ángulo de 90° en 5 s. Calcular su velocidad angular y la velocidad lineal de los puntos del borde si el ancho de la puerta es de 50 cm. R. 0,314 rad/s, 0,157 m/s.

- measure reactants precisely. ( first choice)

- stir to the reaction take place. ( second choice)

- wait patiently until the reaction completes. ( fourth choice)

- make sure to recover as much copper as possible. ( last choice)

answer: the metamorphic rocks are formed when they are exposed to high pressure and high temperatures. this happens when one of the earth's plates comes in contact with the other plate by traveling in opposite directions, straight into each other or slipping under one another. the friction that is caused by this activity results in   melting of rocks and when it cools they are known as metamorphic rocks. this process needs a controlled amount of pressure and temperature otherwise it may turn into magma.