Newton's laws of conclusions now answer
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Answer:
all object continues to be in its state of rest or uniform motion unless acted upon by an external unbalanced force. 2. the rate of change of momentum of an object is proportional to the unbalanced force in the direction of the force.
For every action there is an equal but opposite reaction . Conclusion for Newton's 3rd law of motion is based on the statement of Newton's 3rd law of motion which states that "for every action, there is an equal and opposite reaction".
Newton's first law
Sir Isaac Newton was a scientist who lived in England (1642-1727) who was interested in the motion of objects under various conditions. He suggested that a stationary object will remain stationary unless a force acts on it and that a moving object will continue moving unless a force slows it down, speeds it up or changes its direction of motion. From this he formulated what is known as Newton's first law of motion:This property of an object, to continue in its current state of motion unless acted upon by a net force, is called inertia.
Let us consider the following situations:
An ice skater pushes herself away from the side of the ice rink and skates across the ice. She will continue to move in a straight line across the ice unless something stops her. Objects are also like that. If we kick a soccer ball across a soccer field, according to Newton's first law, the soccer ball should keep on moving forever! However, in real life this does not happen. Is Newton's Law wrong? Not really. Newton's first law applies to situations where there aren't any external forces present. This means that friction is not present. In the case of the ice skater, the friction between the skates and the ice is very little and she will continue moving for quite a distance. In the case of the soccer ball, air resistance (friction between the air and the ball) and friction between the grass and the ball is present and this will slow the ball down.Newton's second law of motion (ESBKT)
According to Newton's first law, things 'like to keep on doing what they are doing'. In other words, if an object is moving, it tends to continue moving (in a straight line and at the same speed) and if an object is stationary, it tends to remain stationary. So how do objects start moving?
Let us look at the example of a \(\text{10}\) \(\text{kg}\) box on a rough table. If we push lightly on the box as indicated in the diagram, the box won't move. Let's say we applied a force of \(\text{100}\) \(\text{N}\), yet the box remains stationary. At this point a frictional force of \(\text{100}\) \(\text{N}\) is acting on the box, preventing the box from moving. If we increase the force, let's say to \(\text{150}\) \(\text{N}\) and the box almost starts to move, the frictional force is \(\text{150}\) \(\text{N}\). To be able to move the box, we need to push hard enough to overcome the friction and then move the box. If we therefore apply a force of \(\text{200}\) \(\text{N}\) remembering that a frictional force of \(\text{150}\) \(\text{N}\) is present, the 'first' \(\text{150}\) \(\text{N}\) will be used to overcome or 'cancel' the friction and the other \(\text{50}\) \(\text{N}\) will be used to move (accelerate) the block. In order to accelerate an object we must have a resultant force acting on the block.
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Now, what do you think will happen if we pushed harder, lets say \(\text{300}\) \(\text{N}\)? Or, what do you think will happen if the mass of the block was more, say \(\text{20}\) \(\text{kg}\), or what if it was less? Let us investigate how the motion of an object is affected by mass and force.