More details
Applying Newton's first law to answer some true/false statements about why objects move (or not).
Applying Newton's first law to answer some true/false statements about why objects move (or not).
Plant cells have a cell wall in addition to a cell membrane, whereas animal cells have only a cell membrane. Plants use cell walls to provide structure to the plant. Plant cells contain organelles called chloroplasts, while animal cells do not. Chloroplasts allow plants to make the food they need to live using photosynthesis.
The idea of the electric field, how it's useful, and explains how the electric field is defined.
Figuring out the acceleration of ice down a plane made of ice.
Forces at a distance are explained by fields (gravitational, electric, and magnetic) permeating space that can transfer energy through space. Magnets or electric currents cause magnetic fields; electric charges or changing magnetic fields cause electric fields.
Magnetism is an interaction that allows certain kinds of objects, which are called ‘magnetic’ objects, to exert forces on each other without physically touching. A magnetic object is surrounded by a magnetic ‘field’ that gets weaker as one moves further away from the object. A second object can feel a magnetic force from the first object because it feels the magnetic field of the first object. The further away the objects are the weaker the magnetic force will be.
An elaboration on how to use Newton's second law when dealing with multiple forces, forces in two dimensions, and diagonal forces.
An elaboration on some of the common misconceptions in dealing with Newton's Third Law. He also shows how to correctly and reliably identify Third Law force pairs.
Basic primer on Newton's First Law of motion.
Newton's Laws of Motion