EducatorSharmin

Average Speed The distance travelled in unit time by an object is called its speed. Average speed is defined as distance travelled per unit time.  For example, if you cycle 2.4 km in 10 minutes, then your average speed would be                        2400 m/ 10 x 60 s                           =  24/6 m/s                          = 4 m/s 1. The distance between Mumbai and Pune is 180 km. A bus takes about 4 hours to cover the distance. What is the average speed of the bus? Solution: Average speed  = Distance / time                           = 180/4 km/h                           = 45 km/h The most commonly used units for speed are km/h and m/s. Speed...

Adaptations of Rice for Wet Environments:   Although rice can grow in dry conditions, it is often grown in 'paddies'- fields where the ground is intentionally flooded. Rice can tolerate growing in water, whereas most of the weeds that might compete with it are not able to do so.   Most plants cannot grow in deep water because their roots do not get enough oxygen. Oxygen is required for aerobic respiration, which provides ATP as an energy source for active transport and other energy-consuming processes such as cell division. Nor, if the leaves are submerged, can photosynthesis take place, because there is not enough CO2 available. This happens because gases diffuse much more slowly in water than they do in the air. Moreover, the concentration of dissolved O2 and dissolved CO2 in water are much less than they are in the air.  Some varieties of rice respond to flooding by growing taller. this allows O2 and CO2 t obe exchanges through the stomata on the leaves. Ethanol is tox...