1. First, invest in a spare inner tube. If you get a puncture on the road it's far easier to change the tube and repair the punctured one later at home. To repair the tube you'll need a pump, tyre levers and a puncture repair kit with patches, sandpaper, a marker and glue.
Mass is a measure of the number of atoms in an object combined with the density of those atoms. Usually people measure mass in kilograms. You can tell how much mass something has by measuring how hard it is to get that thing to change directions or slow down. If you're driving a big truck, for instance, you're going to need a lot stronger brakes to stop the truck than if you were riding a bicycle.
mass noun. 1  1The extent of the area or subject matter that something deals with or to which it is relevant. âwe widened the scope of our investigationâ. 2  2The opportunity or possibility to do or deal with something. âthe scope for major change is always limited by political realitiesâ.