A uniform meter rule of AB is balanced horizontally on a knife edge 15cm from A with a mass of 30kg at A what is the mass of rule and the force exerted on the rule by the knife edge.

At very high pressures, gases become and will eventually a) more dense; become hotter b) more dense; change to a liquid or solid c) less dense; combust d) less dense; turn into a liquid

Física: un futbolista patea hacia el arco con una velocidad de 15m/ah, calcular: a)el alcance para un ángulo de tiro de 25º, b) el tiempo que el balón permanece en el aire.

How does the strength of the electrostatic force between an electron and a proton compare to the strength of the gravitational force between them?