A 40kg girl Climbing a flight Of upstairs expend energy at the
rate of sow. The timetaken for her
to reach a height of 2om is.​

low freq = 100 mhz

low wavelength =101.7m

length = 3x10^8/freq

object 2 because all the other ones are wrong

answer: the metamorphic rocks are formed when they are exposed to high pressure and high temperatures. this happens when one of the earth's plates comes in contact with the other plate by traveling in opposite directions, straight into each other or slipping under one another. the friction that is caused by this activity results in   melting of rocks and when it cools they are known as metamorphic rocks. this process needs a controlled amount of pressure and temperature otherwise it may turn into magma.

answerdmitry mendeleyev made a workable classification of the elements