R= mg cos a + Psin a Note: If the surface is smooth, then F=0
Examples
. A body of mass 5 kg rests on an inclined
plane whose angle of inclination to the
horizontal can be varied. If the coefficient of
friction between the body and the surface of
the inclined plane is 0.3, at what angle does
the body start to slide down from the plane?
Solution
RR
D

Isobars are lines of constant or equal pressure on a weather map. they can be used to find areas of low or high pressure over a broad area, and they can tell us how intense the system may be. on weather maps, you may have noticed areas that have a large l or h over a region with lines circling around them. the l stands for low pressure and h stands for high pressure. the lines circling them are isobars. check out the pressure system and isobars over georgia and florida. what is the present weather in this area ? a) clear and sunny b) cold and cloudy c) changing weather d) lots of precipitation