Which example illustrates a chemical change?

solution:

the spring force applied by a spring with spring constant k can be expressed as

where k acts as the spring constant

and x indicates the spring's deformation

to determine the work completed by the spring

the amount of work done by the spring when moving from x=0 to x=L

substituting the limits x=0 and x=L

we derive the work done in terms of k and L

Answer:

W = -510.98 J

Explanation:

Force = 43 N, 61° SW

Displacement = 12 m, 22° NE

The work done is calculated using:

W = F*d*cos(A)

where A is the angle between the applied force and displacement.

The angle A between the force and displacement is determined as A = 61 + 90 + 22 = 172°

Hence, W = 43 * 12 * cos(172)

This results in W = -510.98 J

The negative result indicates that the work is done contrary to the direction of the force applied.

When helium is released from a compressed container, the decompressed atoms expand and rise, causing the rubber balloon to inflate and float along. In this scenario, helium exists in a gaseous state.

Answer:

Consequently, we find that:

Thus, the most suitable answer would be:

a. vA = vB/4

Explanation:

In this situation, we can establish the following conditions:

both wires share the same length

both wires carry an identical current

Both wires are constructed of the same material, indicating that the electron density (n) remains constant across both wires

We also know that where r signifies the radius.

Given that wires are cylindrical in shape, we can determine the area for each case:

Thus, we conclude that

Now we are aware that the drift velocity of an electron in a wire can be described by:

Where I denotes the current, n is the electron density, e represents the electron charge, and A signifies the area.

By substituting, we arrive at:

So we observe that:

Thus, the most fitting answer is:

a. vA = vB/4

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.