Hey Steven! Are you ready for the science test on forces and feilds?
Of course! The first main topic we should talk about is contact and non contact forces.
Oh gosh no! I studied all night but I still don't get any of it. I'm really nervous, do you think you can help me out?
Thank you so much! We can go study at the library so that it's more quiet.
The next topic we can talk about is the kinds of contact and non contact forces. For contact, there is applied force which is when force is applied to an object by a person or another object. If a person is pushing a desk across the room, then there is an applied force acting upon the object. Another force is spring force which spring force is the force exerted by a compressed or stretched spring upon any object that is attached to it.
To begin with, a contact force is an interaction between objects that touch. For an example, kicking a soccer ball is a contact force. Non contact forces attract or repel, even from distance. For an example, a magnet is a non contact force.
You should also know how to calculate a net force on an object. If one force is acting on an object then the object moves in the direction of the force. If two forces acting in the same direction then you add the forces together and the object moves in the direction of forces. If two force of different strength opposing each other then you subtract the lesser force from the stronger and the object moves in direction of stronger force. If two forces of equal strength opposing each other then the net force is zero since they are balanced.
The next topic we should talk about is how to diagram forces. Some facts that will help you diagram is that a magnitude is determined by the thickness of a force's arrow or length, the thicker the stronger. Gravity is always pulling straight down. The force of gravity acts on an object can be called weight. Friction, drag, or air resistance are always pushing in the opposite direction of motion. Normal is a stable object that has support. Lastly, thrust is direction mechanical energy that is moving an object.
Another topic is how force fields act at a distance and depend on the type of charge. A field is an area of influence that can apply a force between two objects without the two touching. For an example, a magnet's opposite forces attract each other and the same force repel each other. This goes with electrostatic, opposite attracts and same repels. A gravitational force is always pulling down on Earth's atmosphere.
The last topic we can go over is build an electromagnet and investigate the electric and magnetic relationship by changing the strength of the forces. An electromagnet is a soft metal core that comes magnetic when an electric current passes through the coils around the core. You can increase the strength of an electromagnet by the number of coils, a battery, and a wire. The more coils wrapped around the more stronger it is. Some ways that electromagnets are used are electric devices, speakers, and MRI machines.