Please Help with thia question​

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.

Science and technology are interdependent. advances in one lead to advances in the other. give an example of this phenomenon.

If an athlete runs once around a track, back to the starting line, her average velocity is zero. true or false?