How long does it take earth to spin on it axis once?

Your target variable is δf, the magnitude of the difference in frequency between the waves emitted from the sonar device and the waves received by the device after reflecting off the whale. write an expression for δf in terms of the relevant frequencies using the subscript notation introduced above.

Which of the following is not an appropriate unit for acceleration? (kg/12 mihr? m/min/sec cm/30c?

2) why do satelites not fall while revolving around the earth?