One of the absorption lines of hydrogen has a rest wavelength of 656 nm (at rest means with respect to the observer, like in a lab). You observe several stars and measure the wavelength of this same hydrogen absorption line in each star. Based on the measured wavelength of this line, which star is moving towards the Earth the fastest?

the diagram which shows forces as either balanced = same speed or unbalanced = accelerarting

a longitudinal wave moves energy that is to the direction of the wave’s movement. - true

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.