Forces

Physical quantities can be vectors or scalars.ScalarHas only magnitude. It means it can be described by number only, for example mass, charge, speed, time or distance.We can simply add scalars (think that when you have 2kg of apples and 4kg of oranges, you have 6kg of fruits).

VectorsHave both magnitude and direction.We are concerned not only how big is the quantity, but also in which direction does it point. For example velocity describes how quickly an object moves (lets say the car goes 60km/h), but also in which direction (lets say this car goes left).THE ONLY VECTOR YOU NEED TO KNOW NOW IS FORCE. 

FORCEIt is an interaction between two objects.It is measured in Newtons by a force meter.It has both direction and magnitude.(for example we can push a box standing on the floor by applying a force of 6N towards right)Adding forces is different than adding scalars, as they can act in opposite directions.(for example when another person will push the same box to the left with 4N towards left, the RESULTANT FORCE acting on the box will be 2N towards right)

Force is needed to change the way the object moves. For example to make a ball lying on the floor move, you need to kick it. By kicking it you supply force to make it move.When the ball starts to move, its speed increases (it is 0m/s at the start). This process is called acceleration.Force can also change the direction of a moving object.For example when the ball is going towards your goal, you can kick it (apply force) to send it in an opposite direction.

NEWTON'S FIRST LAWSays that when there is NO FORCE acting on an object or the FORCES TOWARDS LEFT AND RIGHT ARE THE SAME (so the resultant force is 0N)the object will be either RESTING or MOVE IN THE SAME WAY (which means that it won't accelerate or change direction).