Gravity
- A natural phenomenon by which all physical bodies attract each other.
- Acts between all objects.
- Anything that has mass has gravity.
- If mass increases, gravity increases.
- Gravity also gets weaker with distance. So, the closer objects are to each other, the stronger their gravitational pull is.
- Gravity is a force that pulls all objects toward each other.
- The force of gravity causes two objects of different weights to fall to the ground at the same time
Friction
- The force applied by a surface as an object moves across it
- Always present when two surfaces rub together.
- The rougher the surfaces are, the harder they press together, the more friction there will be.
- Friction can be reduced by using lubricants (like motor oil)
- Without friction, it would be very hard to slow or stop the motion of objects.
- There are two main types of friction, static friction and kinetic friction. Static friction operates between two surfaces that aren't moving relative to each other, while kinetic friction acts between objects in motion.
Magnetism
- The force of repulsion and attraction between the poles of magnets.
- Poles of a magnet:
- Area where the magnetic force is the strongest. (North & South).
- Like poles of magnets create a repulsive force and the magnets move away from each other.
- Opposite poles of magnets create an attractive force and the magnets move towards each other.
- Iron, Nickel, and Cobalt are magnetic elements.
- Magnetic field: a region around the magnet that is affected by the magnetic forces.
- Electromagnetism: Used to describe how a magnetic field is created by electric currents flowing.
|
|
|