Polly is pushing a box across the floor with a force of 30n the force of gravity is -8n and the normal force is 8n which value could describe the force of friction if polly could not move the box a. -30n b. -8n c. 8n d. 30n

A)

Explanation:

As we know that box is not moving on the floor

so here net force on the box must be balanced

so in horizontal direction as well as in vertical direction net force must be zero

so we can say in vertical direction we have two forces

1) Normal force

2) weight

so we have

similarly in horizontal direction we have

1) Applied force

2) friction force

]

a

explanation:

no diagram was provided, but i'm guessing it's the one i've attached to my answer.

here, a mechanical force turns the rod.   this generates an electric current in the coil, which powers the bulb.

adding a(n) to an electric circuit would increase the magnetic field around a wire;

b. solenoid

a solenoid is a type of electromagnet whose purpose is to generate a controlled magnetic field.

if the purpose of the solenoid is instead to impede changes in the electric current, a solenoid can be more specifically classified as an inductor rather than an electromagnet.