Will someone plz solve the acceleration

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 statement correctly describes the relationship between frequency and wavelength?

Compare the horizontal displacement of the two balls as they travel to the ground. what do you observe?