The minimum speed needed a non-propelled object to escape from the gravitational influence of a massive body, that is to achieve an infinite distance from it. I think
the strength and vitality required for sustained physical or mental activity.
When the ruler is broughı near the inetal knob, it repels electrons in the metal. Electrons move away froni the ruler and down the metal rod. The knob now has a positive charge. The thin pieces of metal foil at the bottom of the metal rod now have a negative charge.
Are breathing hard. This is because cardiovascular exercise makes the heart beat faster which in turn creates a need for more air.