Someone please help!

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.

What is the speed vfinal of the electron when it is 10.0 cm from charge 1?

Whenever the net force on a moving object is zero its acceleration is