SLOW AND FAST CHANGES
• Some changes are very slow.
• They may take hours, days, weeks or months to occur.
• Like: Milk sets into curd in three hours.
• One revolution of earth around the sun takes one year.
• A child grows into an adult in several years.
• Some changes take place so fast that it is difficult to measure the time taken by them.
• Bursting of balloon, breaking of glass.
• Some changes take only a few seconds or a few minutes to occur. These all are called fast changes.