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olga nikolaevna [1]

3 years ago

12

Reflect on your new experiences, what made you uncomfortable and what encouraged you. Did you learn anything new about yourself

on the trip? Traveling can help you improve. Think about your journey and if it helped you grow in any way.

1 answer:

gizmo_the_mogwai [7]3 years ago

3 0

Answer:

keke

Explanation:

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The revolving nosepiece of a compound microscope is used to: a. move the condenser up or down b. change the objective lens c. ad

Jlenok [28]

Answer:

Option B: change the objective lens

Explanation:

The revolving nosepiece is one of the parts of a microscope. Its responsibility is to hold the objective lenses.

6 0

3 years ago

What is the magnitude of the acceleration of a speck of clay on the edge of a potter's wheel turning at 45 rpm (revolutions per

Brilliant_brown [7]

Answer:

$a_{cp}=7.77m/s^2$

Explanation:

The equation for centripetal acceleration is $a_{cp}=\frac{v^2}{r}$ .

We know the wheel turns at 45 rpm, which means 0.75 revolutions per second (dividing by 60), so our frequency is f=0.75Hz, which is the inverse of the period T.

Our velocity is the relation between the distance traveled and the time taken, so is the relation between the circumference $C=2\pi r$ and the period T, then we have:

$v=\frac{C}{T}=2\pi r f$

Putting all together:

$a_{cp}=\frac{(2\pi r f)^2}{r}=4 \pi^2f^2r=4 \pi^2(0.75Hz)^2(0.35m)=7.77m/s^2$

4 0

3 years ago

A planet orbits a star along an elliptical path from point X to point Y, as shown in the figure. In which of the following syste

8090 [49]

Answer:

The correct answer is Option D, the closed system containing the planet and the star.

Explanation:

To start, we need to define mechanical energy: the energy an object has from its motion and position.

The fundamental principle in physics is that the total energy in a closed system stays constant, even if it transforms. By saying "closed system," we refer to a system isolated from its surroundings. Energy never leaves the system; it only moves from one part to another.

This statement only applies to closed systems, however. An open system that interacts with its environment works differently. Energy may enter and leave the system through interaction with external forces, and this includes mechanical energy. For this reason, Option A and Option B are incorrect.

The remaining two options, C and D, only vary with the objects in the closed system. Option D includes the star; Option C does not.

However, we should take a closer look at Option C. Can an object have potential energy with itself? No, it cannot. It only has potential energy with other bodies. If the system is defined as the planet only, the only type of energy present is kinetic energy. We know a planet orbiting a star has more kinetic energy near and more gravitational potential energy further from its star. Thus it has less kinetic energy further from its star and less mechanical energy. Because of this, Option C is incorrect.

The only answer left is Option D. If we define the planet and star as a closed system, we find no net external force acting on it. Consequently, it obeys the law of conservation of energy. From prior reasoning, we know mechanical energy includes potential energy and kinetic energy and that the amounts of these energies vary with its orbit. As a result, mechanical energy is always conserved and always the same. In the end, the correct answer is Option D.

4 0

3 years ago

How long is the photons journey from the milky way to earth

fgiga [73]

Well i’d love to answer your question but its missing some information. firstly the earth is within the milky way galaxy so something cannot travel “from” but if you said “through” the answer would be 299,792,458 meters a second

3 0

3 years ago

A Juggler is juggling a uniform rod one end of which is coated in tar and burning. He is holding the rod by the opposite end and

lyudmila [28]

The vertical speed of the rod varies inversely as the rotational speed for a given number of complete rotations

The equation that gives the vertical velocity, v₀ is $\, \underline{v_0= \dfrac{ g \cdot \pi \cdot n}{ \omega_0 }}$

Reason:

<em>From a similar question, the given parameters appear to be correctly given as follows;</em>

<em>The vertical speed of the rod = v₀</em>

<em>Angular velocity of the = ω₀</em>

Required;

The value of, v₀, so that the rod has made exactly, <em>n</em>, number of turns when it returns to his hand

Where;

n = An integer

Solution;

The time the rod spends in the air is given as follows;

$Height, \ h = u \cdot t - \dfrac{1}{2} \cdot g \cdot t^2$

Where;

g = Acceleration due to gravity

t = Time of motion

When the rod returns to his hand, we have, h = 0, therefore;

$0 = u \cdot t - \dfrac{1}{2} \cdot g \cdot t^2$

$u \cdot t = \dfrac{1}{2} \cdot g \cdot t^2$

$t^2 = \dfrac{u \cdot t }{\dfrac{1}{2} \cdot g } = \dfrac{2 \cdot u \cdot t }{g }$

$Time, \ t = \dfrac{2 \cdot u }{g }$

We have;

$Angular \ velocity, \ \omega_0 = \dfrac{ 2 \cdot \pi \cdot n}{t} \ (required)$

$\omega_0 = \dfrac{ 2 \cdot \pi \cdot n}{ \dfrac{2 \cdot v_0 }{g }} = \dfrac{ g \cdot \pi \cdot n}{ v_0 }$

Therefore;

$The \ vertical \ velocity, \, \underline{v_0= \dfrac{ g \cdot \pi \cdot n}{ \omega_0 }}$

Learn more here:

brainly.com/question/14140053

4 0

3 years ago