Heather Ross EDU 521

4 th grade Science Electricity, Magnetism and Motion The following images will be visual representation on what the students will be learning in the Science Unit

Table of Contents Static Electricity Electric Current Magnet Electromagnet Motion –Forces on objects –Forces in nature Simple Machines –The lever –Pulley and wheel –Other simple machines

Static Electricity

Electric Current

Magnet

Electromagnet

Motion

Motion Changing Places

Forces on Objects –2nd law: "F = ma; acceleration is proportional to force and inversely proportional to the mass of the accelerated object." You are pushing a box across a frictionless surface, if you want to speed up the box faster (increase in acceleration), you push harder (increase in force). If the box was replaced with a heavier. box (increase in mass), you have to push harder (increase in force) to speed it up at the same rate as before If you want to calculate the acceleration, first you need to modify the force equation to get a = F/m. When you plug in the numbers for force (100 N) and mass (50 kg), you find that the acceleration is 2 m/s2

Forces in Nature –3rd law: "For every action there is a equal and opposite reaction." Perhaps the most misconceived law by the public, this law does not mean if the earth pulls you down by the virtue of its mass, it also "hold" you up. –This law means the force that is applied has an equal and opposite counterpart. For instance, if you apply a force to a object, the object applies the same force on you. Therefore, the earth applies a gravitational force on you, and you apply an equal and opposite force on the earth! This force is not noticed due to the second law, the earth is approximately 100,000,000,000,000,000,000,000(10^22) times more massive than any of us but the force is still there. –

Simple Machines.