Select the correct answer A car is moving at a constant speed along a straight line, which statement is true about the forces acting on the car?
The net force acting on the car from all directions is zero.
The net force acting on the car is greater than the car's weight
The net force acting on the car is in the direction of the car's motion
The net force acting on the car is in the opposite direction of the car's motion
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Explanation:

Constant speed => Zero acceleration

Since Fnet = ma, when a = 0, Fnet = 0.

The best answer here is:

"The net force acing on the car from all directions is zero."

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.

russian is not my first language, so i'm afraid i can't write out an answer in russian, but hopefully you can find a way to do so. here's my best translation of the problem: you're given a plot of a particle's position in one-dimensional space over time, and you're asked to find either the total distance traveled by the particle after 6 seconds had elapsed, or the total displacement of the particle after 6 seconds.

if you want the total distance traveled, you would first need to determine the particle's velocity as a function of time, then integrate that over the 6-second interval. we know the position function is quadratic with roots at 0 and 6, so we have

where is unknown. because the position is parabolic, there is symmetry about the midpoint at , and we know that

so that the position function is

which means the velocity is

then the total distance traveled is

so the total distance traveled is 20 m.

on the other hand, if you want to find displacement: the particle starts at and ends at , so its displacement is 0.