Two vectors a is 3i-4j-5k and b is 6i+2j-5k find angle between a and b

The plum pudding model of the atom state that ?

Waves are used in many practical applications to support work, entertainment, and health. one example is the use of ultrasound imaging to safely track the development of a growing fetus. what is a specific example of a practical application of waves in medicine, entertainment, safety, or other fields? provide a brief explanation of how the properties of waves are useful to that application.

The difference between a red shift and a blue shift has to do with wavelength frequency. t or f