In I/GCSE Physics, you will have to know and apply all 3 of Newton's Laws.
Newton's First Law1️⃣
An object will continue to move at a constant velocity unless a resultant force acts upon it.
This means that an object will continue to do whatever it is doing unless an unbalanced force acts upon or the forces already acting upon the object increases or decreases.
For something to move at a constant velocity all the forces must be balanced. If an object has a resultant force of 0 the object will remain stationary or it will continue to move at the same velocity.
Therefore, balanced forces means no change in velocity.
Newton's Second Law2️⃣
Newton's Third Law states that when an unbalanced force acts upon an object it will:
- changeF the direction of the acceleration
- change the magnitude of the acceleration
Acceleration is directly proportional to the resultant force
F=ma
- F being unbalnced forces in Newtons
- m being inertial mass in Kg
- a acceleration in m/s2
Newton's Third Law3️⃣
When two objects interact they exert equal and opposite forces on each other.
This means that with every action the reaction force is equal in size and opposite in direction.
For example, we exert the same amount of force on the Earth as the Earth exerts on us but we are smaller in mass so we don't seem to make a difference on the Earth.
Inertia is the tendancy for motion to remain unchanged
Drafted by Catrina (Physics)