Need asap (worth 20 points)

in the reaction,
1/0x + 235/92u --> 140/54xe + 94/38sr + 2 1/0x + energy

x is a(n)

proton
electron
neutron
positron

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.

The free body diagram shows a box being pulled to the left up a 25-degree incline. the magnitude of the normal force is

What will a positive and a negative charge do if they are separated from each other?