Answer:
5.58 × 10⁻¹¹ N/C
Step-by-step explanation:
Electric force on a charge, F = qE
where,
F is the electric force in Newton (N)
q is the unit charge in Coulomb (C)
E is the electric field intensity in N/C
Also, the weight of an object, W = mg
Where,
w is weight of an object in N
m is mass in kg
g is acceleration due to gravity in m/s²
Now from the question given, the electric force exerted on the proton is equal in magnitude to the proton's weight.
⇒ F = w
qE = mg
making electric field, E the subject of the equation,
E = (9.11 × 10⁻³¹ kg × 9.8 m/s) ÷ 1.6 × 10⁻¹⁹ C
E = 55.8 × 10⁻¹² N/C
E = 5.58 × 10⁻¹¹ N/C