Lisa made the electromagnet shown. (Image above) What can Lisa do to increase the strength of the electromagnet? O She can use a nail with weaker magnetic properties.

O She can change the direction of the nail.
O She can increase the number of wire loops.
O She can reduce the current in the wire.

If correct first gets Brainliest Please hurry this is a timed test( this is second time just in case I didn't go through)

An observer that stands still as the electron moves by him, will observe

Which explanation describes the forces involved for a person to walk down the sidewalk? a. the person's feet push backward on the sidewalk; the sidewalk pushes backward on the person. b. the person's feet push forward on the sidewalk; the sidewalk does not push on the person. c. the person's feet push backward on the sidewalk; the sidewalk pushes forward on the person. d. the person's feet push forward on the sidewalk; the sidewalk pushes forward on the person.

Unpolarized light whose intensity is 1.19 w/ is incident on a polarizer. (a) what is the intensity of the light leaving the polarizer? (b) if the analyzer is set at an angle of = 41.0∘ with respect to the polarizer, what is the intensity of the light that reaches the photocell?