Alkaline earth metals have a low density


true
false

Answers

Answer 1

true

Explanation:

this is because melting point and boiling point decreases down the group because they are held together by attractions between positive nuclei and delocalised electrons


Related Questions

For a system mass of 600g and a hanging weight of 0.50 N, determine the acceleration of the system

Answers

Answer:

A=0.80

Explanation:

a=2×100/time^2. a=2×100/15.86^2. = a=0.80

The acceleration of the system will be 0.833 meters per second square.

What is newton's second law?

The behavior of things is predicted by Newton's first rule of motion when all external forces are equal. The first law, sometimes known as the law of inertia, asserts that if an entity's energies are balanced, its acceleration will be zero meters per second.

When all forces are balanced, an object is said to be in equilibrium and won't accelerate. Newton postulated that an item will only accelerate in the presence of a net or uneven force. An object will accelerate if there is an imbalanced force present, altering its direction, speed, or both.

Let 'm' be the mass of the object in kilogram and 'a' is the acceleration of the object in meters per second square. Then the force on the system is calculated as,

F = ma

For a system mass of 600g and a hanging weight of 0.50 N. Convert the mass of the object into kilogram. Then we have

m = 600 / 1000

m = 0.6 kg

Then the acceleration of the system will be calculated as,

0.50 = 0.6 × a

a = 0.833 meters per second square

The acceleration of the system will be 0.833 meters per second square.

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Brainliest for correct answer :)

Answers

Answer:

B- They both have travelled equal distances in 7 minutes

Hope this helps!

Answer:

B!

Explanation:

Geologists know the past temperature of the planet based on rock and fossil evidence. Why do you think it is difficult to determine what has caused climate change in the distant past?

Answers

Answer: Greenhouse gases affect how much of the Sun's energy the Earth loses back to space. Predicting global temperature change is hard, even though the principle sounds easy. In simple terms, energy reaches Earth from the Sun.

Explanation:

A stone falls from rest from the top of a cliff,a second stone is thrown do wnward from the same height 2sec later with an initial speed of 30m/s.If both stones hit the ground below simultaneously,how high is the cliff?

Answers

Answer:

The cliff is 12.632 meter high.

Explanation:

Each stone experiments a free fall motion, that is, an uniformly accelerated motion due to gravity. We construct the respective equations of motion for each stone:

First stone

[tex]y_{1} = y_{o,1} +v_{o,1}\cdot t +\frac{1}{2}\cdot g\cdot t^{2}[/tex] (1)

Second stone

[tex]y_{2} = y_{o,2} +v_{o,2}\cdot (t-2) +\frac{1}{2}\cdot g\cdot (t-2)^{2}[/tex] (2)

Where:

[tex]y_{1}[/tex], [tex]y_{2}[/tex] - Final height of the first and second stone, in meters.

[tex]y_{o,1}[/tex], [tex]y_{o,2}[/tex] - Initial height of the first and second stone, in meters.

[tex]v_{o,1}[/tex], [tex]v_{o,2}[/tex] - Initial speed of the first and second stone, in meters per second.

[tex]t[/tex] - Time, in seconds.

[tex]g[/tex] - Gravitational acceleration, in meters per square second.

If we know that [tex]y_{o,1} = y_{o,2}[/tex], [tex]y_{1} = y_{2} = 0\,m[/tex], [tex]v_{o,1} = 0\,\frac{m}{s}[/tex], [tex]v_{o,2} = -30\,\frac{m}{s}[/tex] and [tex]g = -9.807\,\frac{m}{s^{2}}[/tex], then we find that time when both stones hit the ground simultaneously is:

[tex]4.904\cdot t^{2} = -30\cdot (t-2)+4.904\cdot (t-2)^{2}[/tex]

[tex]4.904\cdot t^{2} = -30\cdot t + 60 +4.904\cdot (t^{2}-4\cdot t +4)[/tex]

[tex]-30\cdot t +60 -19.616\cdot t +19.616 = 0[/tex]

[tex]49.616\cdot t = 79.616[/tex]

[tex]t = 1.605\,s[/tex]

The height of the cliff is:

[tex]y_{1} = y_{o,1} +v_{o,1}\cdot t +\frac{1}{2}\cdot g\cdot t^{2}[/tex]

[tex]y_{o,1} = 12.632\,m[/tex]

The cliff is 12.632 meter high.

Brainliest for correct answers :)
Please look at both pictures and answer correctly for brainliest

Answers

Answer:

a. 1100 meters.

b. Between B and C

c.1. Between point D and E

c2. Between point D and E

d. 3.7 m/s.

Explanation:

The girl travels the distance of 1100 meters from starting to the end. There is no motion occurs between B and C due to no change of distance value from 200 meters. Between point D and E, the girls covers 500 meters long distance and also covers fastest distance between point D and E because between point D and E, the girl covers 500 meters distance in 30 seconds which is the highest of all. The average speed of the girls is 3.7 meter/seconds if we divide total distance i.e. 1100 meters by time which is 300 seconds.

What is MyPyramid?
a.exercise program
b.health insurance plan
c.method of treating mental illness
d.guidelines for healthful eating

Answers

Answer:

d

Explanation:

lol Hope's this helps lovely

anyone know how to select someone as brainiest?!!!!!!!!!!!!!!!

Answers

you press the button near their answer
Where’s the work????????

Brainliest for correct answer :)

Answers

Answer:

B

Explanation:

The answer is b that is the final speed - initial speed divided by the time taken

Please mark as brainliest

B. If unread carefully, that is the only answer that works.

PLEASE HELP ME
NEED IT FAST WILL GIVE B !! If correct

Answers

Answer:

25% :)

Explanation:

C. Move the light bulb back and forth. No matter where the light bulb is located on the central axis, what is always true about size of the image?

Answers

Answer

It will stay the same!

Explanation:

If you so happen to move something from left to right, the size of it is not being shrunk or expanded in any type of way, shape, or form.

Q11) If you were standing at the top of a building and you dropped a rock.
you noticed that the rock took 5.2 s to hit the ground. Find the total
distance the rock traveled and the speed when the rock hit the ground.

Answers

Answer:

Part A

The distance travel by the rock is approximately 132.496 m

Part B

The speed when the rock hits the ground is approximately 50.96 m/s

Explanation:

Part A

The question is focused on the kinetics equation of a free falling object

The given parameter is the time it takes the rock to hit the ground, t = 5.2 s

For an object in free fall, we have;

h = 1/2·g·t²

Where;

h = The height from which the object is dropped

g = The acceleration due to gravity ≈ 9.8 m/s²

t = The time taken to travel the distance, h = 5.2 s

∴ h = 1/2 × 9.8 m/s² × (5.2 s)² ≈ 132.496 m

The distance travel by the rock, h ≈ 132.496 m

Part B

The speed, 'v', when the rock hits the ground, is given by the following kinematic equation,

v = g·t

∴ v = 9.8 m/s² × 5.2 s = 50.96 m/s

The speed when the rock hits the ground, v ≈ 50.96 m/s.

Explain why tissues in multicellular organisms are supplied with nutrients using a circulatory system.

Answers

Answer:

The tissues in a multicellular organism requires a circulatory system in other to deliver oxygen and food to the tissues while also removing carbon dioxide and metabolic wastes due the complexity of these activities

Explanation:

Multicellular organisms are organisms that are made of more than one cell. the more cells an organism has the more complex certain activities might be for the organism hence the tissues in a multicellular organism requires a circulatory system in other to deliver oxygen and food to the tissues while also removing carbon dioxide and metabolic wastes

Use appropriate units and signficant figures.

You drive 67.0 mi 35.0º south of east and then drive 40.0 mi 20.0º west of south. What is your displacement?​

Answers

Answer:

D = 54.9 mi, 71.6 South of the East

Explanation:

In this exercise it is asked to find the displacement of the body, one of the easiest tasks is to dispose each displacement in a Cartesian coordinate system, let's use trigonometry

* first displacement d₁ = 67.0 mi

the angle is 35 south of east, measured from the axis x θ = -35

             cos -35 = x₁ / d₁

             sin -35 = y₁ / d₁

            x₁ = d₁ cos (-35)

            y₁ = d₁ sin (-35)

            x₁ = 67 cos 35 = 54.88 mi

            y₁ = -67 sin 35 = -38.43 mi

* second displacement d₂ = 40, mi

the angle is 20 to the west of the south, so mean from the axis x is

           θ = 180+ 20 = 200º

           cos 200 = x₂ / d₂

           sin 200 = y₂ / d₂

           x₂ = d₂ cos 200

           y₂ = d₂ sin 200

           x₂ = 40.0 cos 200 = -37.59 mi

           y₂ = 40.0 sin 200 = -13.68 mi

now we can find the displacement in each exercise

            X_total = x₁ + x₂

            X_total = 54.88 -37.59

            X_total = 17.29 mi

            Y_total = y₁ + y₂

            Y_total = -38.43 -13.68

             Y_total = - 52.11 mi

Let's use the Pythagorean theorem to find the displacement

             D = [tex]\sqrt{x_{total}^2 + y_{total}^2}[/tex]

             D = [tex]\sqrt { 17.29^2 + 52.11^2}[/tex]

             D = 54.9 mi

to find the angle let's use trigonometry

             tan θ = [tex]\frac{y_{total} }{x_{total} }[/tex]

             θ = tan⁺¹ \frac{y_{total} }{x_{total} }

             θ = tan⁻¹ (-52.11 / 17.29)

             θ = -71.6º

the negative sign indicates that it is measured clockwise from the x-axis.

In cardinal coordinates it is 71.6 South of the East

Alannah added a strip of zinc to a beaker containing a solution of copper
sulfate, as shown in the photo. She expected to observe the immediate
formation of solid copper in the beaker but saw no evidence of a reaction.
Alannah predicted that the reaction was happening too slowly to observe.
Which statement could best explain this result?

Answers

The solution of copper sulfate was too cold

Explanation:

The lack of an observable reaction when adding a zinc strip to a copper sulfate solution could be due to the zinc not being reactive enough, the reaction occurring too slowly, or an experimental error.

What is the lack of an observable reaction?

The lack of an observable reaction refers to a situation where no visible or measurable change occurs when two or more substances are mixed or brought into contact with each other, even though a reaction was expected based on the chemical properties of the substances involved.

Here in the Question,

The lack of an observable reaction when Alannah added a strip of zinc to a beaker containing a solution of copper sulfate could be due to the following reasons:

Zinc and copper sulfate do not react: It is possible that the zinc strip and copper sulfate solution do not react with each other, leading to no observable change. This could occur if the zinc strip is not reactive enough to displace the copper in the copper sulfate solution.

Reaction is slow: Another possibility is that the reaction between zinc and copper sulfate is occurring but is happening too slowly to be observed. In this case, the reaction rate may be too low to produce an observable amount of solid copper in the beaker in a short period of time.

Experimental error: It is also possible that an error was made during the experiment that prevented the expected reaction from occurring. For example, the concentration of the copper sulfate solution may have been too low, or the zinc strip may have been coated with a layer of oxide that prevented it from reacting with the solution.

Therefore, Zinc may not be sufficiently reactive, the reaction may proceed too slowly, or there may have been a mistake in the experiment if there was no detectable reaction when a zinc strip was added to a copper sulphate solution.

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True or false, not all substances are soluble in water.

Answers

Answer:

I think ur answer would be true

Explanation:

hope this helps

Grant sprints 50 m to the right with an average velocity of 3.0 m/s how many seconds did grant sprint

Answers

Answer:

The time is 16.667 seconds

Explanation:

Velocity ​​is a physical quantity that expresses the relationship between the space traveled by an object and the time used for it. Then, the average velocity results from the quotient between the change in position and the time taken to effect said change:

[tex]velocity=\frac{distance}{time}[/tex]

In this case:

velocity: 3 m/sdistance: 50 mtime: ?

Replacing:

[tex]3 \frac{m}{s} =\frac{50 m}{time}[/tex]

Solving:

[tex]time =\frac{50 m}{3 \frac{m}{s}}[/tex]

time= 16.667 seconds

The time is 16.667 seconds

Grant sprints 50 m o the right with an average velocity of 3.0 m/s.

How many seconds did Grant sprint?

Answer: 16.667

(04.02 LC)


Which of the following is the name for a substance made of two or more types of atoms that are not chemically bonded together? (2 points)


Select one:

a. Compound

b. Mixture

c. Solute

d. Molecule

Answers

Answer: mixture

Explanation: mixture contains two or more substances which are not chemically bonded together

Answer:

B. Mixture

Explanation:

An object is placed on a surface. A student tries to apply various combinations of forces on the object. Which pair of forces will not move the object?

Answers

Answer:

See Explanation

Explanation:

The question is incomplete, as there are no diagrams or options to provide more information to the question.

The general explanation is as follows:

For the object not to move

(1): The forces acting on the object must opposite each other. i.e. if force A acts at the right (or positive direction), force B will act at the left (or negative direction).

(2) The two forces must be equal.

So, for instance:

If the pair of forces are 5N and 5N in opposite directions, the object wil not move.

However, if one of the forces is greater, the object will move towards the direction of the greater force.

Pls help I want to give more points to people this is for 100. yes 100 points

Who is number 15 on the Kansas City Chiefs

Answers

Answer:Patrick Mahomes

Explanation:

Answer:

Patrick Lavon Mahomes II

Explanation:

1- An object of weight 2N is fired upwards to a height of 5 m.
Calculate gain in potential energy.​

Answers

Answer:

PE =  98

Explanation:

PE =mgh

PE= 2 x 9.8 x 5

PE =  98

I hope this helps a little bit.

What can astronomical objects that have changing magnetic fields do

Answers

Answer:

During an excursion or a reversal, the magnetic field is considerably weakened and allows many more cosmic rays to reach the surface of the planet. These energetic particles from space can be damaging to life on Earth if too many reach the surface.

Explanation:

Radio waves may generate astronomical bodies with fluctuating magnetic fields. A further explanation is below.

Electrical charges nanoparticles, as well as molecules, moved via the circular or spiraling route of the magnetic fields. Somewhat on windsurfing spacecraft, various radio astronomy or communications tools named WAVES documented as well as captured a day of explosions of something like the Sun's chromosphere as well as the electromagnetic radiation of our observable universe.

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Which formula uses mass in the equation?

Answers

The mass can be calculated by dividing the net force acting on an object by the acceleration of the object. When talking about net force, we use the units kilogram meter per second squared. This is also known as a Newton. The units for acceleration is meters per seconds squared, and the units for mass are kilograms.

Difference between dynamo and generator

Answers

Answer:

Dynamos and Generators convert mechanical rotation into electric power.

Dynamo - a device that makes direct current electric power using electromagnetism

Generator - used to describe an alternator that creates AC power using electromagnetism.

Explanation: so dynamo makes direct electric power using electromagnetism. A generator creates AC power using electromagnetism

an organism that cannot make its own food called

Answers

Answer:

heterotroph

Explanation:

Answer:

a predator cannot make its own food

Cynthia forgot to put the fabric softener in the wash. As her socks tumbled in the dryer, they became charged. If a small piece of lint with a charge of +1.25 E - 10 C is attracted to the socks by a force of 3.0 E - 6 N, what is the magnitude of the electric field at this location?

Answers

Answer:

E = 24000 N/C = 24 KN/C

Explanation:

The electric field experienced by a test charge is given by the following formula:

[tex]E = \frac{F}{q}\\\\[/tex]

where,

E = Electric Field = ?

F = Force of attraction = 3 x 10⁻⁶ N

q = Charge on piece of lint = 1.25 x 10⁻¹⁰ C

Therefore, using these values in the equation, we get:

[tex]E = \frac{3\ x\ 10^{-6}\ N}{1.25\ x\ ^{-10}\ C}\\\\[/tex]

E = 24000 N/C = 24 KN/C

If I keep F constant in F=ma, what is the relationship between m and a?

Answers

Answer:

If F is a constant, we can take f = 1

f = m×a

ma = 1

therefore we can say that force is hence proportinal to the product of mass and acceleration.

list the factor that affect the speed of sound in gases​

Answers

Temperature, frequency, pressure and density

why must the lamina swing freely in physics​

Answers

Answer:

Unless the lamina is able to move freely under the influence of gravity, you do not know where to draw that line.

Explanation:

How many joules of heat energy are needed to raise the temperature of 10.0 g (0.0100 kg) of aluminum from 22 K to 55 K, if the specific heat of aluminum is 897 J/kg * K. Explain your answer

Answers

Answer:

296.01 J

Explanation:

From the question,

Q = cm(t₂-t₁)....................... Equation 1

Where Q = quantity of heat, c = specific heat capacity of aluminium, m = mass of aluminium, t₁ = Initial temperature, t₂ = Final temperature

Given: c = 897 J/kg.K, m = 0.01 kg, t₁ = 22 K, t₂ = 55 k

Substitute these values into equation 1

Q = 897×0.01×(55-22)

Q = 897×0.01×33

Q = 296.01 J

Hence 296.01 Joules of heat is required.

1. What is the mass of an object moving at 13 m/s and having 3042 J of kinetic energy?​

Answers

Answer: 36 Kg

Explanation:

Ke= 1/2MV^2

Plug in the kinectic energy (3042 J) and solve for M.

3042= 1/2 (M) (13^2)

M= 36 Kg

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