2. What is this about? In Lesson 1 we investigated moving objects in space. In Lesson 2 we discussed how to use power tools in space. In Lesson 3 we discovered what happens to liquids in space. In Lesson 4 we bring it all together by looking at Newton’s Laws as they apply to a microgravity environment.
3. Newton’s First Law of Motion There are two parts to Newton’s First Law of Motion: An object at rest tends to remain at rest unless acted upon by an outside/unbalanced force If you sit a ball down it will stay where you left it unless someone or something moves it. An object in motion tends to remain in motion unless acted upon by an outside/unbalanced force If you kick the ball it will keep going unless it rubs on the ground, falls to the ground because of gravity, slows because of the air….
4. Newton’s First Law in Microgravity The first part of Newton’s First Law of Motion is an object at rest. If you sit a pencil down in the shuttle while it is on orbit what will happen to it? The second part is an object in motion. What would happen if you gave that pencil a push?
5. Newton’s Second Law of Motion F=mA Force is equal to the mass and acceleration of an object This also deals with inertia which is the resistance to a change in velocity If you try to push a stopped car it is hard to get moving. You need force to accelerate the mass. You do not want to be in front of the car you just got started moving. The car has a mass and acceleration and therefore a force.
6. Newton’s Second Law of Motion in Microgravity You are an astronaut on orbit that must grab a satellite and put in the cargo bay of the shuttle. The satellite has a large mass. It is tough to get it started in the direction you want it to go. What happens if you grab it with the robotic arm of the shuttle and you move it (accelerate it) too fast?
7. Newton’s Third Law of Motion For every action there is an equal and opposite reaction. This is one we have discussed and one that you have a lot of experience with. You push on a wrench and it pushes back on you. If you can put enough force on the wrench it will make the bolt or screw or…. Tighten.
8. Newton’s Third Law of Motion in Microgravity What happens if you tighten down a bolt in microgravity and the bolt stops but you are still putting pressure on the bolt? How would you be able to continue to put an unequal and opposite force on the bolt so that you can continue to tighten it?
9. So… In this lesson we will be putting Newton’s Laws to the test.
