21+10=31 because you can see that 21 and 10 are in metres while 12 is in seconds so 21+10=31 is the answer.
Hello there.
<span>Which of the following is an example of the concepts of growth and development functioning together? <span>
</span>
</span><span> C. Children learning to print their names
</span>
As the bright sun shines upon the water, the water slowly dissapears. This is an example of physical change because here the water is just transformed into water vapour. So only the state and the shape of the substance has changed. Its originality remains absolutely intact. In the second case where the same sunlight gives energy to the surrounding plants to convert water and carbon dioxide into sugar and oxygen gas, it is a chemical change. here new substances are formed and the identity of the original substances are lost.In chemical reactions, the mass of the product will always be the same as the mass of the reactants.
<span>The amount of solar energy available varies by location on earth, the time of the day at that location, the season and weather conditions. Rain, fog, and clouds will lower the amount of solar power available to gather and there are fewer hours of sun available in different seasons (winter for North America). To gather solar power, you also need a large area. This can be lessened by conditions such as snow, so that even on a sunny day, covered panels will collect less energy.</span>
Motion is a change in position measured by distance and time.