Question

A uniform electric field exists in a region between two oppositely charged plates. An electron is released from rest at the surface of the negatively charged plate and strikes the surface of the opposite plate, 1.95 cm away, 14.7 ns later. (a) What is the speed of the electron as it strikes the second plate? (b) What is the magnitude of the electric field?​

Answer 1

Answer:

Explanation:

The charge of an electron  = 1,6 × 10^-19 C

The mass of an electron  = 9,109 ×10^-31 kg

According to the second equation of motion -  

s = 1/2 at²

1,95*10² = 1/2 a(14,7*10^-9 sec)²

a = 2 × 1,95 × 10^-2/(216,09 × 10^-18)

a = 0,018 × 10^16 = 1,8*10^14 m/sec^2

v = a × t

v = 1,8 × 10^14² × 14,7*10^-9  

v = 26,46 × 10^5 m/sec

F = m × a

F = 9,11*10^-31 × 1,8*10^14 m/sec^2

F = 16,4 × 10^-17 N

E = F/q  

E = 16,4 × 10^-17 N/1,6*10^-19 C  

E = 10,25 × 10^2 V/m