Specific details

• Inertia


  The tendency for an object to continue in the same state of motion is called inertia. An object's inertial mass is a measure of how difficult it is to change the velocity of an object.
• Newtons 1st law


  If an object is stationary or moving at a constant velocity, then the resultant force acting on the object is zero. It is in equilibrium
• Newton's 2nd law


  The acceleration of an object is directly proportional to the resultant force acting upon it, and inversely proportional to the mass of the object
• Newtons 3rd Law


  Whenever 2 objects interact, the forces they exert on each other are equal in magnitude and opposite in direction
• The conservation of momentum


  In a closed system the total momentum before an event ( such as a collision) is equal to the total momentum after the event.
• Thinking distance = reaction time x speed
• stopping distance = thinking + braking distance
• braking distance = work done / force
• Explain why the velocity of a satellite changes as it orbits earth

  The force of gravity causes the satellite to accelerate, the acceleration causes a change in direction, velocity changes because of direction
• Explain why refraction takes place at a boundary between deep and shallow water

  Velocity is slower in shallow water, so the edge of the wave entering the shallow water slows down but other parts of the wave continue hence changing direction
• Jumping from a higher height allows a skydiver to reach a much higher speed, why?

  The higher the altitude the less dense the air is , so the air resistance on the skydiver who was higher up was less, so the skydiver was able to accelerate for longer before reaching terminal velocity so the skydiver was able to accelerate for longer.
• Uses of EM waves--> radio

  Radio waves have a very long wavelength which means they can diffract around the surface of the Earth.

  Short radio waves like long waves can be transmitted long distances this is because they are reflected by the ionosphere.

  Includes the use of bluetooth, TV and FM radio
• Uses of EM waves--> Microwaves


  Used for satellite communication as they can pass through earths watery atmosphere.

  For satellite TV, the signal from a transmitter is transmitted into space where it is picked up by a satellite receiver dish. This transmits the signal back in different directions where it is picked up by a satellite dish.