Objects repel and attract because of a thing called electrostatic attraction. When objects have the same charge (positive or negative), then they will repel, and if they have opposite charges then they will attract
Force = mass x acceleration
force = 2500kg x (20m/s / 10m/s)
force = 2500kg x 2m/s^2
force = 5000kg m/s^2 = 5kN
i hope this is right (^^)
It all comes to the doppler effect, the red shift means that the galaxy is moving away from us. The redshift is a result from the doppler effect, so as the galaxy moves away the wavelength expands, increasing the wavelength which responds to the red light.
a compound microscope is used for viewing samples at high magnification<span> 40 - 1000x, which is achieved by the combined effect of two sets of lenses: the ocular lens in the eyepiece and the objective lenses close to the sample.</span>
