Friction is the resistance that one surface or object encounters when moving over another. The force of friction always acts in the direction opposite to that of the applied force. In general, smooth surfaces produce less friction than rough surfaces.
Sliding friction is when two objects that are solid slide over each other. An example of this would be when a puck slides across the ice rink because the ice is a solid and so is the puck.
Projectile Motion & Elastic Force
What is projectile motion? Projectile motion is for example when you drp a ball what if you were to throw it horizontally instead. That is projectile motion. A projectile is basically when an object is thrown.
Gravity is when an objects are being pulled together by a force. An example of gravity is the force that causes a ball you throw in the air to come down again.
Free Fall is when only one force is acting on an object. In free fall, the force of gravity alone causes an object to accelerate in the downward direction. I also learned that free fall causes objects to accelerate at the same time depending on its masses. Free fall can cause two objects to automatically drop at the same distance and hit the ground at the same time.
Vocabulary 1. accelerating 2. masses
An elastic force that stretches or pulls matter together is called tension.
Elastic forces is, for example when you squeeze a sponge the sides come together but it doesn break. That is compression. Compression is an elastic force that squeezes/pushes matter together.