The ability of a metal to react with air and water is a
property.
O chemical, physical, respectively
O physical, chemical, respectively
o physical, physical, respectively
O chemical, chemical, respectively

c. aluminium

d. it cannot travel through glass

e. mass of 55kg, takes 25s to gain a height of 15m

Answer:

Gamma rays have so much energy they could harm people on Earth. People are protected from gamma rays by Earth's atmosphere. The atmosphere absorbs gamma rays, preventing them from affecting life on Earth. Because gamma rays cannot penetrate Earth's atmosphere, scientists use satellites in space to study them.

Answer:

Explanation:

because gamma rays have so much energy they could harm people on earth

Answer:

A

Explanation:

Consider a question you may not have considered before. Suppose you have a mole of sodium in a container that contains nothing that it will react with. A mole of anything is 6.02 * 10^23 (in this case atoms).

Suppose that every one of those atoms has contributed 1 electron to something.

Do you think it would be safe to touch the container knowing that there are 6.02 * 10^23 positive charges all eager to get another electron, because they don't like repelling each other.

Safe or not? I'll give you a hint. A lightning bolt does not contain anywhere near 6.02*10^23 charges. No where near.

So -- since you never get a shock from just touching anything, There must not be electrons or ions present.

The answer is A

Answer:

the train is moving relative to the boy

Explanation:

When the train is on the road, it moves with respect to the Earth at a speed of 35 km / h. When we arrive at the station we change the reference system from the ground to the boy who is in the station, therefore the speed of the train can change

               v ’= v + u

where v is the speed of the train with respect to the boy, v is the speed with respect to the ground and u the speed of the boy with respect to the ground

In general, the people in the station are still, that is, their speed with respect to the ground is zero, consequently the speed of the train does not change.

The correct answer is that the train is moving relative to the boy.

Answer: The scientist named Isaac Newton proposed this universal law of gravitation.

It is given that the bodies in this universe attract one another.

It is required to name the scientist who propounded this statement​.

According to Newton's law of gravitation, every object in the universe attracts every other object with a force that is proportional to the multiplication of the masses and inversely proportional to the square of the distance between the objects. This is the universal law that means this is a constant term that can't be changed with respect to place which was proposed by Isaac Newton in 1687.

Therefore, Isaac Newton proposed this universal law of gravitation.

Learn more about gravitation here:

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Answer:

10 pa

Explanation:

4kg* 10 (or 9.8m/s2) = 40

40N /4m2 =10

Answer:All of the elements in a period have the same number of atomic orbitals. For example, every element in the top row (the first period) has one orbital for its electrons. All of the elements in the second row (the second period) have two orbitals for their electrons.Explanation:

Answer:

It tells us the principle quantum shell in which the element lies in. In other words, it shows the total number of electron shells the atom has

Answer:

The fraction of the protons would have no electrons [tex]=1.88\times 10^{-10}[/tex]

Explanation:

We are given that

Amoeba has total number of protons=[tex]1.00\times 10^{16}[/tex]

Net charge, Q=0.300pC

Electrons are fewer than protons=[tex]1.88\times 10^6[/tex]

We have to find the fraction of protons would have no electrons.

The fraction of the protons would have no electrons

=[tex]\frac{Fewer\;electrons}{Total\;protons}[/tex]

The fraction of the protons would have no electrons

=[tex]\frac{1.88\times 10^{6}}{1.00\times 10^{16}}[/tex]

[tex]=1.88\times 10^{-10}[/tex]

Hence, the fraction of the protons would have no electrons [tex]=1.88\times 10^{-10}[/tex]

Answer:

In order to improve visibility

Explanation:

Infrared telescopes are made using infrared cameras that contain infrared detectors which are solid-state and are maintained at very cold (cryogenic) temperatures

Infrared radiation is absorbed by water vapor which is present in the Earth's atmosphere, leading to the limitation of the use of infra red telescopes at high altitudes such as mountains, high flying planes or satellites

Answer:

The fundamental frequency of the stretched string is:

[tex]f=[/tex] [tex]\frac{1}{2} \sqrt{\frac{T}{L} }[/tex] [ T = Tension and μ = mass per unit length]

Here,

 μ = [tex]\frac{m}{L} = \frac{Vp}{L} = Ap[/tex]

[tex]f= \frac{1}{2} \sqrt{\frac{T}{Ap} }[/tex]

If T is halved and A is doubled,

[tex]f= \frac{1}{2} \sqrt{\frac{T'}{A'p} } = \sqrt{\frac{1}{2* 2* A* p} } = \frac{1}{2} (\frac{1}{2} \sqrt{\frac{T}{Ap} } = \frac{1}{2} f[/tex]

Thus, the frequency is reduced to half if its tension is halved and the area of cross-section of the string is doubled.

When the tension is halved and the area of cross section is doubled, the frequency increases by a factor of 1.414.

The frequency of transverse vibration of a stretched string is calculated as follows;

[tex]f = \frac{1}{2l} \sqrt{\frac{T}{\mu} }[/tex]

where;

[tex]f = \frac{1}{2l} \sqrt{\frac{T}{\mu} }\\\\f = \frac{1}{2l} \sqrt{\frac{Tl}{m} } \\\\f = \frac{l^2}{2l} \sqrt{\frac{T}{m} } \\\\f = \frac{A}{2l} \sqrt{\frac{T}{m}}[/tex]

when the tension is halved and the area of cross section is doubled, the frequency is calculated as;

[tex]\frac{f_1}{A_1 \sqrt{T_1} } = \frac{f_2}{A_2\sqrt{T_2} } \\\\f_2 = \frac{f_1 A_2\sqrt{T_2}}{A_1 \sqrt{T_1} }\\\\f_2 = \frac{f_1 \times 2A_1\sqrt{0.5T_1} }{\sqrt{T_1} }\\\\f_2 = \frac{f_1 \times 2A_1 \times 0.7071\sqrt{T_1} }{\sqrt{T_1} }\\\\f_2 = 1.414 f_1[/tex]

Thus, when the tension is halved and the area of cross section is doubled, the frequency increases by a factor of 1.414.

Learn more about tension in a string here: https://brainly.com/question/25743940

Answer:

no

Explanation:

ans should be correct

Coulomb, unit of electric charge in the metre-kilogram-second-ampere system, the basis of the SI system of physical units. ... The coulomb is defined as the quantity of electricity transported in one second by a current of one ampere.

Mark me as brainliest....

Answer:

a) pressure means force acted on a body per unit area

Answer:

The action of measuring the size, length, or amount of something, as established is called measurement.

Explanation:

“Measurement” is the act of determining a target's size, length, weight, capacity, or other aspect. ... To use measurement tools as necessary. It is also appropriate to say that measurement is done by a worker using a measurement system, and instrumentation is done by a technician.

Answer:

–625 J

Explanation:

So, we got this formula for the work

W=mgd(Cosθ)

but remember when it's liftin somethin, its work gon be against the work of gravity, so

Cos180°= –1

W=500×1.25×(–1)

W= –625 J

Answer: H2CO3

Explanation:

Answer:

The unit of the equation P·V = n·R·T is the Joules which is the same as the unit of energy

Explanation:

The unit of energy is Joules, with symbol J

The given equation for an ideal gas is P·V = n·R·T

Where;

P = The pressure of the gas with units Pascals, Pa

V = The volume of the gas, with units m³

n = The number of moles with unit moles

R = The universal gas constant = 8.314 J/(mol·K)

T = The temperature, with units, Kelvin, K

Therefore, we get;

P·V has unit 1 Pa × 1 m³ = 1 N/m² × 1 m³ = 1 N·m = 1 Joule

Similarly, we get

n·R·T with units n mole × 8.314 J/(mol·K) × 1 K = 8.314·n Joules

Therefore, P·V = n·R·T, has the unit of Joules which is the same unit with energy.

Answer:

Explanation:

Assuming the squirrel is jumping off the ground, here's what we know but don't really know...

v₀ = 4.0 at 50.0°

So that's not really the velocity we are looking for. We are dealing with a max height problem, which is a y-dimension thing. Therefore, we need the squirrel's upward velocity, which is NOT 4.0 m/s. We find it in the following way:

[tex]v_{0y}=4.0sin(50.0)[/tex] which gives us that the upward velocity is

v₀ = 3.1 m/s

Moving on here's what we also know:

a = -9.8 m/s/s and

v = 0

Remember that at the very top of the parabolic path, the final velocity is 0. In order to find the max height of the squirrel, we need to know how long it took him to get there. We are using 2 of our 3 one-dimensional equations in this problem. To find time:

v = v₀ + at and filling in:

0 = 3.1 - 9.8t and

-3.1 = -9.8t so

t = .32 seconds.

Now that we know how long it took him to get to the max height, we use that in our next one-dimensional equation:

Δx = [tex]v_0t+\frac{1}{2}at^2[/tex] and filling in:

Δx = [tex]3.1(.32)+\frac{1}{2}(-9.8)(.32)^2[/tex] and using the rules for adding and subtracting sig fig's correctly, we can begin to simplify this:

Δx = .99 - .50 so

Δx = .49 meters

Answer:

We can use  2 g H = v2^2 - v1^2    or

v2^2 = 2 g H + v1^2

Since 88 ft/sec = 60mph   we have 30 mph = 44 ft/sec

The object will return with the same speed that it had initially so the object

starts out with a downward speed of 44 ft/sec

Then v2^2 = 2 * 32 ft/sec^2 * 160 ft + 44 (ft/sec)^2

v2^2 = (2 * 32 * 160 + 44^2) ft^2 / sec^2 = 12180 ft^2/sec^2

v2 = 110 ft/sec

Answer:

The acceleration of proton is 5.56 x 10^10 m/s^2 .

Explanation:

initial velocity, u = 0

Electric field, E = 580 N/C

final speed, v = 10^6 m/s

(a) Let the acceleration is a.

According to the Newton's second law

F = m a = q E

where, q is the charge of proton and m is the mass.

[tex]a= \frac{q E}{m}\\\\a = \frac{1.6\times10^{-19}\times 580}{1.67\times 10^{-27}}\\\\a= 5.56\times 10^{10} m/s^2[/tex]

Complete question is;

A cylinder of compressed gas is at a temperature of 23°C. It is cooled until it reaches the pressure of 2000kPa. It has to be cooled to 90K before this happens. Calculate the starting pressure of the gas

Answer:

Starting pressure = 604 KPa

Explanation:

We are given;

Initial temperature; T1 =23°C = 298 K

Final temperature; T2 = 90 K

Final pressure; P2 = 2000 KPa

From gay lussac's law, we know that;

P1•T1 = P2•T2

P1 = (P2•T2)/T1

P1 = (2000 × 90)/298

P1 ≈ 604 KPa

Answer:

The package reaches the ground in  

4.67 s

and hits the ground with a speed of  

33.8 m/s

.

Explanation:

Answer: depth= 1875m

Explanation: divide t by 2 because its echo it will go and come back thats why we divide it with 2

Then apply formula Depth(d)=velocity (v)/time (t)

Putting values we get ,

d=1500/0.4

d=1875m

Answer:

1. 45 m

2. 50 m/s

Explanation:

From the question given above, the following data were obtained:

Initial velocity (u) = 20 m/s

Time (t) = 3 s

1. Determination of the position (i.e height)

Time (t) = 3 s

Acceleration due to gravity (g) = 10 m/s²

Height (h) =?

h = ½gt²

h = ½ × 10 × 3²

h = 5 × 9

h = 45 m

2. Determination of the velocity.

Initial velocity (u) = 20 m/s

Time (t) = 3 s

Acceleration due to gravity (g) = 10 m/s²

Velocity (v) =?

v = u + gt

v = 20 + (10 × 3)

v = 20 + 30

v = 50 m/s

Answer:

[tex]d=58m[/tex]

Explanation:

From the question we are told that:

Initial Speed [tex]U=12m/s[/tex]

Time [tex]T=5.6s[/tex]

Angle [tex]\theta=30[/tex]

Generally the  Newton's equation for motion is mathematically given by

[tex]d=d'+ut+\frac{at^2}{2}[/tex]

[tex]d=12cos30*5.6[/tex]

[tex]d=58m[/tex]

Answer:

b)3:2

Explanation:

The dispersive power is the reciprocal of the focal length:

[tex]P=\frac{1}{f}[/tex]

Given the ratio of focal lengths:

[tex]\frac{f_1}{f_2} = \frac{2}{3}\\\\\frac{\frac{1}{P_1}}{\frac{1}{P_2}}=\frac{2}{3}\\\\\frac{P_2}{P_1}=\frac{2}{3}\\\\\frac{P_1}{P_2}=\frac{3}{2}[/tex]

Therefore,

P₁ : P₂ = 3 : 2

Hence, the correct option is:

b)3:2

Answer:

The correct alternative is Option b (are influenced by social trends).

Explanation:

There is no connection between the other three choices. Thus, the answer is right.