For the diffraction image below, the detector was positioned 200 mm from the crystal and the wavelength of x-rays was 1.5 what unit cell dimensions can be derived from the spacings of reflections within the central zone [(1,0,0), (0,10,)] on this diffraction image (a* = 1.75 mm [horizontal direction]; b* = 2.5 mm [vertical direction])? what is the unit cell dimension (c = ? ) parallel to the x-ray beam

The answer is as follows in the photo

The boat's velocity relative to the riverbank can be resolved into two components. the component going north is 2.7 m/s and the component going west is 1.2 m/s.we add these two vectors and then find the magnitude of the resultant to get the speed.the magnitude of the resultant vector from adding can be obtained by the pythagorean theorem.    to two significant figures, the boat's speed relative to the riverbank is 3.0 m/s.