Physics Edexcel GCSE-Paper 2 Revision

SECTION 1-FORCES AND MOTION

Momentum

• A vector quantity is influenced by both magnitude and direction.
• A scalar quantitiy is influenced only by magnitude but not by direction.
• MOMENTUM- momentum= mass * velocity  measured in (kg m/s)
• Momentum is a vector quantity.
• Force = Change in Momentum/ Time taken
• Momentum and collisions- Momentum is always conserved ( momentum before collision= momentum after collision).
• Elastic collissions-Collisions in which no kinetic energy is lost, Partially elastic collision are those where some of the KE is lost and an inelastic collision is one where the objects collide and stick together.
• CAR SAFETY:
• Crumple zones collapse during a collision and increase the time during which the car is decelerating, seat belts make sure that reduced deceleration applies to a persons body as well, they increase the time for which the person comes into contact with forces, reducing force.
• NEWTONS THIRD LAW- for every action there is an equal and opposite reaction.

Turning Effect of Forces

• Moment (Turning Effect)= Force * Distance- measured in (Nm)
• For a force to have the biggest turning effect, it must be perpendicular to the door (line of action) perpendicular to the door.

SECTION 2-ELECTRICITY

Voltage

• Voltage is the energy transferred per unit charge passed.
• A volt is the amount of joules per coulomb.

Electric Charge

• Insulating materials include rubber, plastic, wood, glass. Conducting materials are most metals.
• The loss of electrons on an uncharged object, produces a positive charge on the object, and the gain of electrons on an uncharged object produces a negative charge.
• Insulating materials can be charged by friction…