**Answer:**

Makes it hard to go to sleep at night

**Explanation:**

**Answer:**

Net force = 25N and in the right direction

**Explanation:**

**mass of box, m = 50kg**

Force of block = 150N

Friction force = 125N

150 - 125 = 25N

the force applied to the block is greater than the friction force. there the force applied will overcome the friction force and move in the right direction of the force applied

<span>i believe the answer is

D. Wool is an excellent thermal insulator because heat flows through it very slowly.</span>

I'm assuming your question refers to the train travels 81 km in 2 hours, as in that's the total distance covered versus the speed for those 2 hours, whereas the 90 km in 2 hours the second time around is the total distance not speed I would assume.

Now... if it was going 81 km for the first 2 hours and 90 km for the second 2 hours then the average speed would be the mean of these numbers, with that being 85.5 km. Though, I doubt that's your question.

With that said, 81 km covered by 2 hours and 90 km covered by 2 more hours. To acquire the km an hour average, we'll have to divide the distance by how many hours it traveled:

81 / 2 = 40.5

90 / 2 = 45

Meaning the train was going 40.5 km an hour for the first 2 hours and 45 km an hour for the second 2 hours. Now, to find the mean:

40.5 + 45 = 85.5 / 2 = 42.75

In-case you were wondering, the mean is the sum of all the numbers in a set, divided by the total amount of numbers in that set, take for instance:

3, 5, 9, 2, 1, 5. -> There are 6 numbers in this set.

3 + 5 + 9 + 2 + 1 + 5 = 25 -> 25 is the sum of these numbers.

25 / 6 = 4.2 (estimated) -> 4.2 is roughly the mean or average between the original set.

Anyhow, with that aside the average speed between this I would believe would be 42.75 km an hour. I hope that helps, have a great rest of your day! ^ ^

| | Ghostgate (Alter) | |

Explanation:

The charge (positive or negative) is always on the surface in the conductors. So, if the plates have substantial thickness, the charge is distributed throughout the surface. We know from the question that the bottom plate is charged positively, so an equal amount of negative charge must be distributed on the lower surface of the upper plate.

The direction of the E-field is always directed from positive to the negative charge. Since the plates have flat surfaces, the electric field lines are straight, except the edges. In most college level questions this effect is negligible, that is why in most questions the plates are considered very large.