SCIENCE 6 3RD PERIODICAL

• Friction is a contact force. It is a force that exists when one surface slides over another.
• Static friction is a type of friction that keeps objects at rest
• Kinetic friction is a type of friction that is present when an object is moving
• Gravitational force is a downward force acting on an object
• There are two types of friction: static and kinetic.
• Kinetic friction can be sliding, rolling, or air friction.
• Sliding friction acts on dry, solid objects sliding on a surface.
• When you attach wheels to the object to move it, another type of kinetic friction takes over, rolling friction.
• Air friction acts on an object that is falling or moving through the air. For example, when you are running really fast you experience wind resistance.
• Objects that go up eventually go down. The gravitational force of Earth pulls them down. Gravitational force, or gravity, is the only downward force that acts on every object.
• What will happen to the basketball after it shoots through the ring?

  it will go back down
• What is gravitational force?

  Only downward force that acts on every object.
• Energy is the ability to do work or any activity that requires action.
• Electrical energy


  Present in appliances like TV, Radio, Light bulbs and more
• Mechanical energy

  • Potential energy
  • Kinetic energy
• Nuclear energy


  Stored in the nucleus of an atom and is released during nuclear reactions
• Light energy


  A form of radiant energy that is visible to the human eye
• Mechanical energy


  Energy that an object has due to its position or motion
• Sound energy


  Energy possessed by sound waves or vibrating objects and/or particles
• Kinetic energy


  Energy possessed by objects that are moving
• Thermal energy


  Energy possessed by an object due to the movement of particles within it
• Chemical energy


  Chemicals are converted to energy like the glucose in your food
• Potential energy


  Stored energy or at rest
• Inclined Plane is also known as ramp, one of its end is higher than the other.
• Lever is a long rigid bar that rotates around the fulcrum. The fulcrum is the pivot point of a lever.
• A screw can be viewed as a thin inclined plane wrapped around a cylinder. It can hold things together.
• Wedge can be viewed as a moving inclined plane used to cut objects.
• A wheel attached to an axle is the best description of this type of simple machine. The axle is the rod or pile found at the center of the wheel, which allows the wheel to rotate.
• Pulley is a simple machine that is used to redirect a force.