Answer:
a) Watt is a derived unit because it's not a “base unit.”
b) The atomic clock is suitable for measuring time because natural atomic oscillations happen at a higher frequency and as a result they are more stable.
c) There is fluctuation in time measured by a pendulum clock because the pendulum rod changes in length slightly with changes in temperature, causing changes in the rate of the clock. An increase in temperature causes the rod to expand, making the pendulum longer, so its period increases and the clock loses time.
D) The weight of an object is more at pole and less at equator of the earth because the distance of the pole is less than the distance of the equator from the centre of the earth.
e) The weight of an object on the moon is about one-sixth the weight it would have on the earth because the moon's gravitation force is determined by the mass and the size of the moon. Hence, the weight of an object on the moon is 1/6th its weight on the earth.
A neutral object must have _______________ A. An equal amount of positive and negative charges B. no charges present at all C. more positive than negative charges D. more negative than positive
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
show that pv=nrt has the same unit with energy
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.
If an object is thrown in an upward direction from the top of a building 160 ft high at an initial speed of 30 mi/h, what is
its final speed when it hits the ground? (Disregard wind resistance. Do not reflect negative direction in your answer.)
ft/s
110 fus
100 ft/s
097 ft/s
91 ft/s
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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
What is meant by measurement? l
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.
explain why it is important that the Earths atmosphere absorbs gramma rays emitted by the sun
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
A squirrel jumps into the air with a velocity of 4 m/s at an angel of 50 degrees. What is the maximum height reached by the squirrel?
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
The most successful types of plants on Earth are
Answer:
The angiosperms dominate Earth's surface and vegetation in more environments, particularly terrestrial habitats, than any other group of plants. As a result, angiosperms are the most important ultimate source of food for birds and mammals, including humans.
Explanation:
plz mark brainlest
An amoeba has 1.00 x 1016 protons and a net charge of 0.300 pC. Assuming there are 1.88 x 106 fewer electrons than protons, If you paired them up, what fraction of the protons would have no electrons
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]
Please help
Will give the brainliest!
c. aluminium
d. it cannot travel through glass
e. mass of 55kg, takes 25s to gain a height of 15m
Does direction matter when determining distance?
yes
no
Answer:
no
Explanation:
ans should be correct
what is the meaning of coulomb in physics ????
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....
A cylinder of compressed gas is at a temperature of 23 degrees. 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
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
What is this?
Picture
Answer:
may be upside down alphabet :"T"
Explanation:
A box has a mass of 4kg and surface area 4m². Calculate the
pressure exerted by the box on the floor.
Answer:
10 pa
Explanation:
4kg* 10 (or 9.8m/s2) = 40
40N /4m2 =10
This question is divided into two parts. This is part (a) of the question. A proton accelerates from rest in a uniform electric field of 580 N/C. At some later time, its speed is 1.00 x 106 m/s. (a) Find the magnitude of the acceleration of the proton. (Mass of the proton is 1.67 x 10-27 kg and charge is 1.60 x 10-19 C) (in the following options 10^10 m/s^2 is 1010 m/s2)
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]
Find the sum. Express the answer in scientific notation. (1.54 x 10^6)+(6.15 x 10^6)
Answer:
[tex] { \tt{(1.54 \times {10}^{6}) + (6.15 \times {10}^{6}) }} \\ = { \tt{(1.54 + 6.15) \times {10}^{6} }} \\ = { \tt{7.69 \times {10}^{6} }}[/tex]
a stone is projected horizontally with 20 m/a from top of a tall building. calculate it's position and velocity after 3s neglecting the air resistance
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
difine scalar quantity
Scalar quantity are physical quantities that have just magnitude, not direction.
It is always positive.Examples: Speed, distanceTRUE OR FALSE. if an object does not change its position at a given time interval, then it is at rest or its speed is zero or not accelerating
Answer:
true
Explanation:
a body can only be accelerating and have speed if it's in motion
What happen to the frequency of transverse vibration of a stretched string if its tension is halved and the area of cross section of the string is doubled?
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;
T is the tension on the stringμ is the mass per unit length[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
What information does the period number give about an atom?
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
A car starts from rest .If its acceleration is 1.5m/s^2 in 1.5 seconds. then calculate the distance traveled by it.
Answer:1.6875 m
Explanation:
Formula= 1/2 x at^2
A hot air balloon is ascending at the rate of 1.2m/s and is 80m above the ground when a package is dropped over the side.
1) How long does the package take to reach the ground?
2) With what speed does it hit the ground?
Answer:
The package reaches the ground in
4.67 s
and hits the ground with a speed of
33.8 m/s
.
Explanation:
Two lenses having f1:F2=2:3 has combination to make no dispersion.Find the ratio of their dispersive power?a)2:3 b)3:2 c)4:9 d)9:4
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
why is the tin of regular coke sink in water?
Answer:
This happens because the tin is made of estañum, and the estañum is denser than the water.
Remember the relation:
density = mass/volume
The general rule is that if an object is denser than water, it will sink
If an object is less dense than water, like a piece of wood, it will float.
And if an object has the same (or nearly the same) density as water, it will float, but fully submerged.
Based on that, we can conclude that the tin will sink because it's density is larger than the density of the water.
Can somebody help me understand this
a ship using an echo sounding device receives an echo from the bottom 0.8 seconds after the sound is emitted. if the velocity of sound in water is 1500m as what is the depth of water?
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
The categories specified in the DSM: a. change from edition to edition b. are influenced by social trends c. may reflect Western cultural biases d. a, b, and c
Answer:
The correct alternative is Option b (are influenced by social trends).
Explanation:
DSM seems to be a mental sickness seems to be a psychiatric disease. Mental diseases are disorders of healthcare that affect emotions, thought, as defined mostly on the American Psychological Association website.Psychological disorders are socially associated or connected, workplace and familial issues as well as problems.There is no connection between the other three choices. Thus, the answer is right.
A weightlifter lifts a 500 N barbell with no acceleration, 1.25 meters. How much work did she do in lifting the weights?(step by step)
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
Sebastián se encuentra en una parada de trenes. El tren n° 15 pasa sin detenerse a una velocidad de 35 km/h. Si situamos el sistema de referencia en Sebastián, ¿el tren n° 15 está en reposo o en movimiento?
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.