The gravitational force acting on the elevator is 4500N. Explanation: The parameters provided indicate that the force exerted by the elevator is F = 4500 N. The elevator does not accelerate. According to Newton's third law, the force exerted by the cable matches the gravitational force on the elevator, which represents its weight (W), and the elevator's motion stands as follows: F = W + (Mass of elevator × Acceleration of elevator). Therefore, F = W + (Mass of elevator × 0) = W, which leads us to F = 4500 N = W. The net force on the elevator can be expressed as F - W = 0, confirming that the gravitational force on the elevator equals W = 4500N.
Answer:

Consequently, the temperature difference across the material will be 
Explanation:
In this case, we apply the Fourier Law of heat conduction expressed by the following equation:
(1)
Where k = thermal conductivity = 0.2 W/ mK
A= 1m^2 denotes the cross-sectional area
Q= 3KW signifies the heat transfer rate
is the temperature difference we need to determine
represents the thickness of the material
To isolate

from equation (1), we obtain:

Initially, we convert 3KW to W, resulting in:

With all variables accounted for, we can substitute and calculate:

Thus, the temperature difference across the material will be 
- The greatest potential energy increase occurs when the charge travels north. This happens because the charge is negative, which means it gains potential energy when moving
in the same direction as the field (in contrast, a positive charge moving along the field loses potential energy, converting it to kinetic energy). The potential energy gained is calculated as the charge multiplied by the distance moved:

- The next largest increase occurs as the charge moves east. Here, the change in potential energy is actually zero since the charge moves perpendicular to the field, traversing points with constant potential. Therefore, there is no variation in potential energy in this case:

- Finally, when the charge moves south, it experiences a reduction in potential energy. This is due to moving
against the electric field, and since it is a negative charge, it loses potential energy in this direction, which transforms into kinetic energy. Thus, in this scenario:
Answer:

Explanation:
In this scenario, we determine the initial velocity as follows:

The final velocity in this instance can be expressed as:

It is noted that transitioning from 7m/s to 13m/s takes 8 seconds. We can apply a specific kinematic equation to find the acceleration for the first part of the journey:

Solved for acceleration, we find:

For the subsequent route, we assume constant acceleration and that the train continues for 16 seconds, beginning with an initial velocity of 13m/s from the previous segment, allowing us to calculate the final speed via the following formula:

Substituting into the equation yields:
