Suppose that the particle in Exercise in 1.33 is an electron projected with velocity vx= 2.0 × 106 m s−1. If E between the plates separated by 0.5 cm is 9.1 × 102 N/C, where will the electron strike the upper plate?

Question 1.34: Suppose that the particle in Exercise in 1.33 is an electron projected with velocity v_x= 2.0 × 10⁶ m s⁻¹. If E between the plates separated by 0.5 cm is 9.1 × 10² N/C, where will the electron strike the upper plate? (| e | =1.6 × 10⁻¹⁹ C, m_e = 9.1 × 10⁻³¹ kg.)

Answer:

 method -1

Velocity of the particle, v_x = 2.0 × 10⁶ m/s Separation of the two plates, d = 0.5 cm = 0.005 m

Electric field between the two plates, E = 9.1 × 10² N/C Charge on an electron, q = 1.6 × 10⁻¹⁹ C

Mass of an electron, m_e = 9.1 × 10⁻³¹ kg

Let the electron strike the upper plate at the end of plate L, when deflection is s. Therefore,

  

Therefore, the electron will strike the upper plate after travelling 1.6 cm.

method -2