Required practical's
Absorption and emission of infrared radiation
Take 2 identical cans, one with light shiny surface one with matt, black surface.
Fill each can with the same volume of hot water at the same temp.
Leave the cans for the same length of time (20 mins) and measure the temperature in both cans.
The can with the lower temperature will have the surface that is the best emitter of infrared radiation.
Fill each can with the same volume of cold water at the same temp.
Place both cans in the sunlight for the same length of time (30 mins) and measure temp of both cans.
The can with the higher temperature will have the surface that is the best absorber of infrared radiation.
Newtons laws of motion
Newtons first law of motion
P8 - Resultant forces
States that of the forces acting on an object are balanced, the resultant force on the object is zero and -
If the object is at rest it will stay as rest.
If the object is moving, it will carry on moving at the same speed and in the same direction.
Newtons second law of motion
P10 - Forces & acceleration
States that the acceleration of an object is
Inversely proportional to the mass of the object - for a given force, a more massive object will have a lesser acceleration
Proportional to the resultant force on the object - when there is a greater resultant force, the object has greater acceleration
Newtons third law of motion
States that when 2 objects interact with each other, they exert equal and opposite forces on each other
P8 - Forces between objects
Driving force - when a car is driven forwards there is a force from the tyre on the ground pushing backwards - caused by friction.
The forces are always the same e.g. frictional forces.