Para que una bloque de madera de 60n iniciara su deslizamiento con una velocidad constante sobre una mesa de madera, se aplico una fuerza de 21n, calcula el coeficiente de fricción dinámico entre las dos superficies

Which one of the following research methods can show cause and effect

Which of the following situations is impossible? a) an object has velocity directed east and acceleration directed east. b) an object has zero velocity but non-zero acceleration. c) an object has constant non-zero velocity and changing acceleration. d) an object has velocity directed east and acceleration directed west. e) an object has constant non-zero acceleration and changing velocity.

What would be the strength of earth's gravitational field at a point where an 80.0 kg astronaut would experience a 80% reduction in weight