Answer:
A) He finds the same value of q / m for different materials
, B) y = ½ (q / m) E L² / v₀ₓ²
, C) v = E / B
, D) B = 2.13 10⁻⁶ T, E) For the first part I have two off-center points., For the second part I can center one point but the other is off center
Therefore the third statement is correct
Explanation:
Part A
Thomson's experiments are the first proof that the atoms that until now were considered indivisible were constituted by different elements, in these experiments Thomson himself the ratio q / m of several cathodes and always found the same value, which allowed to establish that In atoms there are two types of particles, some of which are mobile and others are still.
When examining his statements the correct one is: He finds the same value of q / m for different materials
Part B
For this part let's use Newton's second law
F = ma
q E = m a
a = q / m E
We use the kinematic relationship
y = voy t - ½ to t²
x = v₀ₓ t
The initial vertical velocity of electrons is zero
y = ½ a (x / v₀ₓ)²
We replace
y = ½ (q / m) E L² / v₀ₓ²
Part C
If there is no deflection, the electric and magnetic forces are the same and in the opposite direction
Fm = Fe
q v B = q E
v = E / B
Part D
We replace
y = ½ (q / m) E L² / (E / B)²
y = ½ (q / m) L² B² / E
If we do not want any deflection the magnetic field has to return the electrons the amount that they lower y = -4.12 cm
-4.12 10⁻² = ½ q / m 0.12² B² / 1.1 10³
-16.97 10⁻⁴ = 6.54 10⁻³ B² q / m
B² = -2.59 10⁻¹ q / m
q / m = -1.758 10¹¹ C/ kg
B = √ 0.259 1.758 10¹¹ = √ 4.55 10⁻¹²
B = 2.13 10⁻⁶ T
Part E
As the charge that the two particles is different
For the first part I have two off-center points.
For the second part I can center one point but the other is off center
Therefore the third statement is correct
