Two long straight wires enter a room through a window. One carries a current of 2.9A into the room, while the other carries a cu

Answer:

The period of a wave is the duration it takes to complete one full oscillation, such as from one peak to the next trough.

Since the period is expressed in microseconds, it needs to be converted into seconds.

The conversion is:

Accordingly, the wave's period in seconds is .

Answer:

Explanation:

When calculating Hall voltage, it is crucial to have the current, magnetic field strength, length, area, and number of charge carriers available. The Hall voltage can be expressed using the equation:

Where:

i= the current

B= the magnetic field strength

L = the length

n = the number of charge carriers

e= charge of an electron

We need to replace values and solve for n:

As a result, the charge carrier density is

Answer: The frequency is 1714.3 Hz

Explanation: The calculation is derived from the Doppler effect formula.

Since the source is approaching the observer, the observer's velocity is considered positive.

Refer to the attached document for the detailed derivation

Answer:

B. Truck X was ahead, not truck Y.

Explanation:

Let's analyze the information provided.

Truck X moved from the point (0,20) to (2.8,50). This indicates that it began at the 20th kilometer and reached 50 km in 2.8 hours. Thus, its speed is v1 = (s2 - s1) / t

v1 = (50 - 20) / 2.8

v1 = 10.7 km/h

Given that it started from the 20th km, it indeed had a head start. Since the line on the graph is linear, this shows its speed was constant without any change in direction.

On the other hand, Truck Y's movement went from the origin (0,0) to (5,20), meaning it took 5 hours to travel 20 km, resulting in a speed of v2 = 20 / 5

v2 = 4 km/h

Again, the straightness of its graph line signifies it maintained a constant speed in a single direction.

Thus, it is evident that Rosa erred in her assumption that Truck Y had a head start.