Question

In an electricity experiment, a 1.20 g plastic ball is suspended on a 57.0 cm long string and given an electric charge. A charged rod brought near the ball exerts a horizontal electrical force F⃗ elec on it, causing the ball to swing out to a 22.0 ∘ angle and remain there.

A: What is the magnitude of F⃗ elec?

Express your answer with the appropriate units.

B: What is the tension in the string?

Express your answer with the appropriate units.

Answer 1

Ans:-

Given data :-m= 1.2g = 0.0012 d= 0.57m,θ = 22deg

Vertically, the forces acting on the ball are the vertical component of tension, and its weight. Horizontally, there is the horizontal component of tension and the electrostatic force.

Vertical:

∑F = Tcosθ - mg = 0

Horizontal:

∑F = Tsinθ - Fe = 0

Now determine the tension using the vertical equation:

T = mg/cosθ

T = (0.0012 kg)(9.8 m/s²) / cos22

T = 0.0127 N

Now, using the tension and the horizontal equation determine the electrical force:

Fe = Tsinθ

Fe = (0.0127 N)(sin22)

Fe =0.00475 N