P4- Explaining Motion
OCR 21st Century
- Created by: Abi_xx
- Created on: 11-08-14 20:06
View mindmap
- P4- Explaining Motion
- Forces
- A FORCE occurs when 2 objects INTERACT
- The forces in an INTERACTION PAIR are 1. equal in size 2. Opposite in direction and act on different objects
- AIR RESISTANCE : Air tries to slow down a sky diver, the skydiver pushes the air out of their way (equal and opposite force)
- GRAVITY : 2 masses are attracted to each other eg You and Earth with an equal and opposite force
- ROCKET AND JET ENGINES : Engine pushes gas backwards and gas pushes rocket forward
- The forces in an INTERACTION PAIR are 1. equal in size 2. Opposite in direction and act on different objects
- Forces and Motion
- ARROWS on diagrams are used to represent 1.The size of the force 2.Direction the force is acting in
- Arrows are always draw with the tail touching the object
- If MORE THAN 1 force acts on an object they will : 1.Add up if they are in the same direction 2.Subtract if different directions
- The overall effect is called RESULTANT FORCE
- ARROWS on diagrams are used to represent 1.The size of the force 2.Direction the force is acting in
- There is always a DRIVING FORCE and a COUNTER FORCE
- If the driving force is 1.< counter force = speed increase 2.Equal to the counter force = constant speed in a straight line 3.>counter force=decrease in speed
- A FORCE occurs when 2 objects INTERACT
- Kinetic Energy
- The amount of K.E an object has depends on 1.Mass and 2.Velocity
- K.E (Joules, J) = 1/2 x Mass (kg) x Velocity squared (m/s(squared)
- Work and Energy
- When work is done : 1.On an object, it gains energy 2.By an object it loses energy
- Work done by a force (j) = Force (n) x Distance moved in direction of force (m)
- When a force makes an objects velocity increase 1.Work is done on the object by the force 2.The object gains K.E
- Some of the energy will be dissipated (lost) as heat
- Gravitational Potential Energy
- When an object is lifted above the ground 1.Work is done by the lifting force against gravity 2.The object has the potential to do work when it falls
- Change in G.P.E (J) = Weight (N) x Vertical Height difference (M)
- To Find G.P.E you use WEIGHT not mass
- Forces
Similar Physics resources:
Teacher recommended
Comments
No comments have yet been made