# A(n) ____ is a collection of 105 to 106 stars in a region 10 to 30 pc in diameter. The stars in the collection tend to be more than 109 years old and mostly yellow and red stars.

Open cluster

Explanation:

Open cluster is the group of stars of number up to few thousand which were formed from same cloud and had approximately same age. They are mostly red and yellow stars and these stars are bound loosely by the mutual gravitational attraction and the stars become disrupted by the close encounters with other clouds of gas and clusters ss these stars orbit galactic center.

## Related Questions

Explain the relationship between velocity and acceleration. Are these scalar or vector quantities?

A scalar is something that only has speed without a DIRECTION while a vector has direction. acceleration is a vector and mass is a scalar.
Acceleration is the rate of change of velocity. They're both vectors.

A 4-kg mass moving with speed 2 m/s, and a 2-kg mass moving with a speed of 4 m/s, are gliding over a horizontal frictionless surface. Both objects encounter the same horizontal force, which directly opposes their motion, and are brought to rest by it. Which statement best describes their respective stopping distances? A) Both masses travel the same distance before stopping.
B) The 2-kg mass travels twice as far as the 4-kg mass before stopping
C) The 2 kg mass travels greater than twice as far
D) The 4-kg mass travels twice as far as the 2-kg mass before stopping

B) The 2-kg mass travels twice as far as the 4-kg mass before stopping

Explanation:

As we know that both mass have same horizontal force opposite to their motion

So we will have

now the stopping distance of an object moving with initial speed v is given as

so here we have

for other object we have

B) The 2-kg mass travels twice as far as the 4-kg mass before stopping

Which of the following is not an example of an abiotic factor? a. plants b. air c. temperature d. soil Please select the best answer from the choices provided A B C D

The living beings in an ecosystem are named biotic factors. Living beings involve plants, creatures, bacteria, parasites and many more. The non-living components of an ecosystem are named abiotic factors. In an ecosystem, few abiotic factors are sunshine, temperature, climatic gases, water, and clay.

Plants are not an example of an abiotic factor.

Further Explanation:

Many factors affect the environment such as some factors determines how much the tree can grow, why birds are migrating one place to another, and where the plants and animals are found. There are mainly two types of factors that influence the environment are

• Biotic
• Abiotic

Abiotic factors are referred as a non-living part of an environment that can easily influence living organisms. These factors are very crucial for living organisms. Every plant and animal requires these factors to live. Without these factors organism can become dehydrated, and week. Examples of Abiotic factors are:

• Water
• Sunlight
• Temperature
• Oxygen
• Soil

Biotic factors are referred to as all the living parts of an ecosystem. For example, animals and plants are biotic factors. These living things of the ecosystem interact with each other in different ways. Thus, plants are part of biotic factors and not part of abiotic factor.

Subject: Biology

Chapter: Ecology

Keywords:

Biotic, abiotic, sun, light, water, oxygen, plant, animal, non-living, living, ecosystem, organism, tree, grow, bird, migration.

Sampling error can be reduced by __________. A. none of the these affect sampling error
B. utilizing simple random samples
C. increasing the sample size
D. decreasing the sample size

C. increasing the sample size

Explain how Newton's third law is applied when a rocket ship is being launched?

Newton's Third Law states that "every action has an equal and opposite reaction". In a rocket, burning fuel creates a push on the front of the rocket pushing it forward. This creates an equal and opposite push on the exhaust gas backwards.

Name and describe an alternative renewable energy source in a complete sentence. Hint-Kenetic energy is the energy of motion,and potential energy is related to position.

A example of an alternative renewable energy source is wind energy. I hope that helps.

A block of unknown mass is attached to a spring of spring constant 7.3 N/m and undergoes simple harmonic motion with an amplitude of 12.7 cm. When the mass is halfway between its equilibrium position and the endpoint, its speed is measured to be 32.2 cm/s. Calculate the mass of the block. Answer in units of kg

0.8516 kg

Explanation:

K = 7.3 N/m

A = 12.7 cm

y = A/2, v = 32.2 cm/s

Use the formula for the speed of mass

Now,

Where, m is the mass of block.

m = 7.3 / (2.93 x 2.93) = 0.8516 kg

Consider this situation: A child is holding onto a tree rope and swinging through the air. Of the forces listed, identify which act upon the child.
a. Normal Force
b. Gravity Force
c. Applied Force
d. Friction Force
e. Tension Force
​f. Air Resistance Force

If a child is holding onto a tree rope and swinging through the air, then the force acting upon the child would be gravity force, therefore the correct answer is option B.

What is gravity?

It can be defined as the force by which a body attracts another body toward its center as the result of the gravitational pull of one body and another,

As given in the problem statement if a  child is holding onto a tree rope and swinging through the air, then we have to find the force acting on the child,

The only force that is acting on the child would be  Gravity Force.

Thus, If a child is holding onto a tree rope and swinging through the air, then the force acting upon the child would be gravity force, therefore the correct answer is option B.

brainly.com/question/4014727

#SPJ5

The answer would be b) Gravity force

A charged particle (q = −8.0 mC), which moves in a region where the only force acting on the particle is an electric force, is released from rest at point A. At point B the kinetic energy of the particle is equal to 4.8 J. What is the electric potential difference VB − VA?

The electric potential difference of the given particle is; 600 V

What is the Potential Difference?

We are told that the charge is released from rest and then at point B it is moving with a kinetic energy of 4.8 J.

From law of conservation of energy, we can say that gain in kinetic energy of the charge is equal to the loss in electrostatic potential energy.

Thus;

K.E = qVA - qVB

K.E = q(VA - VB)

Where q = -8mC = -8 * 10⁻³ C

4.8 = (-8 * 10⁻³)(VA - VB)

VB - VA = 4.8/(-8 * 10⁻³)

VB - VA = 600 V