In a two-dimensional Cartesian system, the x-component of a vector is known, and the angle between vector and x-axis is known. W
hich operation is used to calculate the magnitude of the vector? a. dividing by cosine
b. dividing by sine
c. multiplying by cosine
d. multiplying by sine
The kinetic energy of the electron is where is the mass of the electron and v its speed. Since we know the value of the kinetic energy, , we can find the value of the speed v:
is the mass of the electron and v its speed. Since we know the value of the kinetic energy, 
, we can find the value of the speed v: