Friction is a force that occurs when two materials rub together. Friction always acts to oppose (prevent or stop) the movement of an object.
What is drag?
Drag is another name for friction that occurs when an object moves through air or water.
How can friction be reduced and increased
Friction can be reduced if the surfaces of the two materials are lubricated (with water or oil etc)
Friction can be increased by making one or more of the surfaces rougher or pressing them together more strongly
What is mass?
The mass of an object is the amount of matter or 'stuff' it contains. The more matter an object contains, the greater its mass. Mass is measured in kilograms or grams. The mass does change with its location
What is weight?
Weight is the effect of gravity on the mass of an object.
Weight is a force, so it's measured in newtons.
Gravity on earth is a constant and equal to approximately 10n kg -1.
How do you calculate the weight of an object?
Weight force = Mass x gravity
Therefore, a 1 kg mass weights 10 N (weight = 1kg x 10 N kg-1 )
Draw the diagram to figure out velocity, distance, and time. (VERY DANGEROUS TROUGH)