An electron is orbiting a nucleus which has a charge of 19e, under the action of the coulomb force at a radius of 1.15 × 10-10 m

a) Average velocity: 2.8 m/s

b) Average velocity: 5.2 m/s

c) Average velocity: 7.6 m/s

Explanation:

a)

The car's position over time t can be described by

where

To find the average velocity, we divide the displacement by the elapsed time:

At time t = 0, the position is:

At time t = 2.00 s, the position is:

This leads us to the displacement of

The duration for this interval is

Therefore, the average velocity during this period is

b)

At time t = 0, the position is:

At time t = 4.00 s, the position is:

Thus, the displacement is

The time interval is

This yields an average velocity of

c)

The position at t = 2 s is:

And at t = 4 s it is:

This gives us a displacement of

While the time interval is

So the resulting average velocity is

Find out more about average velocity:

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.

Answer:

Explanation:

Each of the processes connected to these molecules varies.

For instance, water that has accumulated in the atmosphere returns to the ground as rain. Cows utilize this water from local water sources. This represents one method in which water transitions from the atmosphere to the cow's body.

Regarding carbon and nitrogen, the air inhaled by cows contains nitrogen, oxygen, carbon dioxide, and other gases. These molecules enter the cow through respiration.

Answer:

a, 71.8° C, 51° C

b, 191.8° C

Explanation:

Given the data:

D(i) = 200 mm

D(o) = 400 mm

q' = 24000 W/m³

k(r) = 0.5 W/m.K

k(s) = 4 W/m.K

k(h) = 25 W/m².K

The heat generation formula can be articulated as follows:

q = πr²Lq'

q = π. 0.1². L. 24000

q = 754L W/m

Thermal conduction resistance, R(cond) = 0.0276/L

Thermal conduction resistance, R(conv) = 0.0318/L

Applying the energy balance equation,

Energy In = Energy Out

This equates to q, which is 754L

From the initial analysis, the temperature at the interface between the rod and sleeve is found to be 71.8° C

Additionally, the outer surface temperature records as 51° C

Furthermore, based on the second analysis, the calculated temperature at the center of the rod is determined to be 191.8° C

Answer:

1. The force applied by the shelf supporting the book.

Explanation:

The free body diagram for the book is represented as follows:

1 - The weight of the book acting downward

2 - The normal force exerted by the shelf upward on the book.

As the book remains stationary, these two forces balance each other, and in accordance with Newton's Third Law, the reactive force equivalent to gravity is opposite and equal to the weight of the book. This reaction force prevents the book from falling off the shelf.