Answer:
Explanation:wave=wavelength×frequency,
On Ramesh’s13th birthday, his father invited all his friends and their relatives. It was a big party with lots of food and DJs. Ramesh didn’t like the loud sound of DJs and asked his father to play it in a low volume so that their neighbours do not get much disturbed and people at the party can also enjoy the music. Ramesh’s father felt good for his wisdom and did as he said.
→Do you think when loud music is played at a party is acceptable to all the people living in, neighbourhood? Give a reason for your answer
→How can you control noise pollution at your end?
Khối lượng ban đầu của mặt trời m⊙ = 2 × 1030 kg trong đó có 71 % là
hydrogen. Trong 5×10^9 năm đầu tiên, mặt trời phát ra năng lượng với công suất
3.86 × 10^26 W, nhờ phản ứng
4p → 4+2He + 2e
+ 2νe + 26 MeV
trong đó bốn proton tổng hợp thành hạt α và tỏa ra năng lượng 26 MeV. Hãy
xác định
a) số hạt proton của mặt trời tại thời điểm ban đầu.
b) số hạt proton của mặt trời tham gia phản ứng trong 1 năm.
c) số hạt proton còn lại trong mặt trời sau 5 × 10^9 năm.
d) thời gian để tiêu thụ hết 10 % số hạt proton còn lại của mặt trời
Answer:
jsgssbvwsvs
Explanation:
ifmd understand
Azam had a metal pencil box and a wooden block on his table. When he touched them, the pencil box felt colder compared to the wooden block. When he measured their temperatures using a thermometer, he found that both the objects were at the same temperatures. What could be the reason for Azam to 'feel' that the pencil box was cooler? * (1 Point) Air around the pencil box was at a lower temperature which made the pencil box colder Wood produces heat and so, must have been at a higher temperature than the pencil box As metal is a better conductor of heat, it drew away heat from his hand faster than the wooden block. Metals are always at a lower temperature than other substances and so, there has been an error in measurement
The third choice is the correct explanation. Don't make me type it all out on my phone.
Use a projectile motion kinematic equation for the vertical motion to find the time t that the ball is in the air, from when it leaves the track until it strikes the floor.
Answer:
The time of flight is [tex]T = \frac{2 u sin A}{g}[/tex].
Explanation:
Let the initial velocity is u and the angle of projection is A.
Use first equation of motion for vertical motion
Let the time to reach the maximum height is t.
[tex]v = u - gt\\\\0 = u sin A - gt \\\\t = \frac{ u sin A}{g}[/tex]
Total time of flight is
T =2 t
[tex]T = \frac{2 u sin A}{g}[/tex]
calculate the electric potential 3mm from a point charge of 16Nc
[tex]4.8 \times 10^8[/tex] volts
Explanation:
The electric potential due to a point charge is given by
[tex]V= \dfrac{1}{4 \pi \varepsilon_{0}} \dfrac{Q}{r}[/tex]
where Q = charge = [tex]16 \times 10^{-9}[/tex] C
r = distance from a point = [tex]3 \times 10^{-3}[/tex] m
[tex]\varepsilon_{0}[/tex] = permitivity of free space
= 8.85×10^-12 C^2/N-m^2
Plugging in the numbers,
[tex]V = \dfrac{1}{4 \pi (8.85 \times 10^{-12})} \dfrac{16 \times 10{-9}}{3 \times 10^{-3}}[/tex]
[tex]= 4.8 \times 10^8[/tex] volts
In a 2-dimensional Cartesian coordinate system the y-component of a given vector is equal to that vector's magnitude multiplied by which trigonometric function, with respect to the angle between vector and y-axis?
a. sine
b. cosine
c. tangent
d. cotangent
Answer:
Option b, cosine.
Explanation:
Below you can see an image that illustrates this situation.
Remember that for a triangle rectangle with a given angle θ, we have:
Cos(θ) = (adjacent cathetus)/(hypotenuse)
In the image, you can see a vector of magnitude M, and the angle θ defined between the vector and the positive y-axis.
In this case, the y-component is the adjacent cathetus and the hypotenuse is the magnitude of the vector.
Then we will have:
Cos(θ) = (adjacent cathetus)/(hypotenuse) = y/M
solving that for y, we get:
y = Cos(θ)*M
Then the y-component is the vector's magnitude multiplied by the cosine of the angle between the vector and the y-axis.
The correct option is b.
Answer:
(b) cosine
Explanation:
In a 2-dimensional Cartesian coordinate system, a vector has a x-component and/or a y-component. To get these components, the magnitude of the vector is resolved with respect to the x-axis and the y-axis by multiplying it (the magnitude) by some trigonometric function with respect to the angle between the vector and the x or y axis.
For example, given a vector A of magnitude A which makes an angle α with the x-axis and an angle β with the y-axis, the x and y components of the vector A can be found as follows;
i. x-component is given by [tex]A_{x}[/tex]
[tex]A_{x}[/tex] = A cos α (with respect to the angle between A and the x-axis) or
[tex]A_{x}[/tex] = A sin β (with respect to the angle between A and the y-axis)
ii. y-component is given by [tex]A_{y}[/tex]
[tex]A_{y}[/tex] = A sin α (with respect to the angle between A and the x-axis) or
[tex]A_{y}[/tex] = A cos β (with respect to the angle between A and the y-axis)
Therefore, the y-component of a vector in a 2-dimensional Cartesian coordinate is given by the product of the magnitude of the vector and the cosine of the angle between the vector and the y-axis.
What is a reasonable measurement for the distance to Neptune?
30 light years
30 kilometers
30 parsecs
30 Astronomical Units
Answer:
30 kilometers is a reasonable measurement
A 10,000J battery is depleted in 2h. What power consumption is this? *
A) 5000W
B) 3W
C) 1.4W
D) 20000W
show your work please
Answer:
P = 1.4 W
Explanation:
Given that,
The work done or the energy of the battery, E = 10,000 J
Time, t = 2 h
We need to find the power consumption. Let it is P. Power is the rate of doing work. So,
[tex]P=\dfrac{W}{t}\\\\P=\dfrac{10,000}{2\times 3600}\\\\P=1.38\ W[/tex]
or
P = 1.4 W
So, the power of the battery is 1.4 W.
which describes a homogeneous mixture
Answer:
A homogeneous mixture is a type of mixture in which the composition is uniform and every part of the solution has the same properties. Example, air
Explanation:
If you warm up the volume of a balloon but keep the pressure the same, you would be using which gas law?
Answer:
Charles law
Explanation:
Charle's law states that the volume (V) of a given gas is directly proportional to the absolute temperature (T) at a constant pressure.
That is;
: V ∝ T
: V/T = K
According to this question, the volume of a balloon is warmed up but the pressure is kept the same. Charles law will be used because it shows the relationship between the volume (V) and the temperature (heat) at a constant pressure (P).
A bullet of mass 0.5 kg is moving horizontally with a speed of 50 m/s when it hits a block of mass 3 kg that is at rest on a horizontal surface with a coefficient of friction of 0.2. After the collision the bullet becomes embedded in the block. How much work is being dne by bullet?
Answer:
Work done by the bullet is 612.26 J.
Explanation:
mass of bullet, m = 0.5 kg
initial velocity of bullet, u = 50 m/s
coefficient of friction = 0.2
mass of block, M = 3 kg
let the final speed of the bullet block system is v.
use conservation of momentum
Momentum of bullet + momentum of block = momentum of bullet block system
0.5 x 50 + 3 x 0 = (3 + 0.5) v
v = 7.14 m/s
let the stopping distance is
The work done is given by change in kinetic energy of bullet
initial kinetic energy of bullet, K = 0.5 x 0.5 x 50 x 50 = 625 J
Final kinetic energy of bullet, K' = 0.5 x 0.5 x 7.14 x 7.14 = 12.74 J
So, the work done by the bullet
W = 625 - 12.74 = 612.26 J
Which one is the dependent variable in distance, force, or work
Answer:
Distance
Explanation:
Work can be defined as the energy transferred to a physical object by exertion of a force on the object to cause a displacement of the object. Thus, work is typically done when a person or simple machine move an object over a distance through the application of a force.
Mathematically, work done is given by the formula;
[tex] W = F * d[/tex]
Where,
W is the work done
F represents the force acting on a body.
d represents the distance covered by the body.
A dependent variable is the event expected to change when an independent variable is manipulated.
Hence, distance is the dependent variable because its value changes with respect to the amount of force exerted on an object.
Write the prime factorization of 32. Use exponents when appropriate and order the factors
from least to greatest
A baby leaves a bowl of food on the floor and crawls westwards to fetch a toy placed 5 m away.At the same time a dog walks eastwards towards the baby. it takes the baby 30 s to reach the toy. The dog walks past the toy to eat the baby's food in the bowl
Determine the position of the dog relative to the baby before they both moved?
Convert Rev/min to rad/s x 2pie/60?
Anyone knows this please?
Answer:
Thus, [tex]\frac{1 rev}{min} =\frac{2\pi}{60} rad/s[/tex]
Explanation:
The angular speed is defined as the rate of change of angular velocity.
Its SI unit is rad/s and other units are rev/min or rev/s.
[tex]\frac{1 rev}{min } = \frac{1 rev}{60 sec}\\\\1 rev = 2\pi rad\\\\So\\\\\frac{1 rev}{min} = \frac{2\pi}{60} rad/s[/tex]
If we warm a volume of air, it expands. Does it then follow that if we expand a volume of air, it warms? Explain.
Answer:
nope don't think so
Explanation:
the heat causes the molecules to move faster therefore expanding in watever it the air is in
Answer:
If the pressure is maintained at a constant value then both statements are equivalent:
P V = n R T Ideal gas equation
if P, n, and R are maintained at constant values then
V = T and the two expressions are equivalent
Two parallel circular plates with radius carrying equal-magnitude surface charge densities of are separated by a distance of How much stored energy do the plates have? A. 120 B. 360 C. 12 D. 37
Answer:
I guess it is A. I am not sure
A charged particle accelerates as it moves from location A to location B. If VA = 260 V and VB = 210 V, what is the sign of the charged particle? positive negative (b) A electron loses electric potential energy as it moves from point 1 to point 2. Which of the following is true regarding the electric potential at points 1 and 2?
Answer:
(a) Positive
(b) Electron gains energy as it moves from A to B.
Explanation:
VA = 260 V
VB = 210 V
An electron moves from lower to higher potential which is negatively charged and a positively charged particle moves from higher to lower potential, so the charge particle is positive in nature.
(a) Positive
(b) No, electron gains energy as it moves from A to B.
If you wanted to know how much the temperature of a particular piece of material would rise when a known amount of heat was added to it, which of the following quantities would be most helpful to know?
a. coefficient of linear expansion
b. specific heat
c. initial temperature
d. thermal conductivity
e. density
Answer:
Option (b) is correct.
Explanation:
The amount of heat required to raise the temperature of substance of mass 1 kg by 1 degree C, is called specific heat of the substance.
The formula of the specific heat is
H = m c (T' - T)
where, m is the mass, c is the specific heat and T' - T is the change in temperature.
So, to know the rise in temperature, by adding the known amount of heat, the specific heat is required.
So, option (b) is correct.
A pitcher throws a curveball that reaches the catcher in 0.61 s. The ball curves because it is spinning at an average angular velocity of 350 rev/min (assumed constant) on its way to the catcher's mitt. What is the angular displacement of the baseball (in radians) as it travels from the pitcher to the catcher
Answer:
22.36 rad
Explanation:
Applying,
ω = θ/t.............. Equation 1
Where ω = angular velocity, θ = angular displacement of the baseball, t = time
make θ the subject of the equation
θ = ωt............... Equation 2
From the question,
Given: ω = 350 rev/min = 350(0.10472) = 36.652 rad/s, t = 0.61 s
Substitute these values into equation 1
θ = 0.61(36.652)
θ = 22.36 rad
Hence the angular displacement of the baseball is 22.36 rad
Một chất điểm chuyển động tròn đều, sau 5 giây nó quay được 20 vòng. Chu kì quay của chất điểm là:
Answer:
T=0,25s
Explanation
5s>20vong 1s>4vong
omega= 8pi
omega=2pi/T
Calculate the terminal velocity of a rain drop of radius 0.12cm
Explanation:
Given that,
The radius of rain drop, r = 0.12 cm = 0.0012 m
The viscocity of air is, [tex]\eta=18\times 10^{-5}\ poise[/tex]
Let the viscous force is, [tex]F = 0.010173\ N[/tex]
The viscous force is given by :
[tex]F=6\pi \eta rv\\\\v=\dfrac{F}{6\pi \eta r}[/tex]
Put all the values,
[tex]v=\dfrac{0.010173}{6\pi 18\times 10^{-5}\times 0.0012 }\\\\v=2498.58\ m/s[/tex]
A circular wire loop is placed near a long, straight, current-carrying wire in which the current is either increasing or decreasing. Draw the situations in which the induced current in the loop counterclockwise?
Answer:
The induced current is counter clockwise if the current is decreasing and towards right.
Explanation:
When the current is decreasing in the wire, the direction of magnetic field at the center of the loop is outwards to the plane of paper which is given by the Maxwell's right hand thumb rule. The magnetic field is decreasing in nature.
So according to the Lenz's law, the induced current is such that which opposes the cause of its production, so that the induced current is counter clockwise.
two blocks are held together with a compressed spring between them on the surface of a slippery table .one block has three times the inertia of the other .when the blocks are released ,the spring pushes them away from each other .what is the ratio of their kinetic energies after the release?
Explanation:
The initial kinetic energy [tex]KE_0[/tex] for both blocks is zero. Let [tex]m_1= m[/tex] and [tex]m_2 =3m[/tex]. So using the conservation law of linear momentum, we can write
[tex]0 = m_1v_1 - m_2v_2[/tex]
or
[tex]v_2 = \dfrac{m_1}{m_2}v_1 = \dfrac{m}{3m}v_1 = \dfrac{1}{3}v_1[/tex]
The final kinetic energies for the two masses are
[tex]KE_1 = \frac{1}{2}m_1v_1^2 = \frac{1}{2}mv_1^2[/tex]
[tex]KE_2 = \frac{1}{2}m_2v_2^2 = \frac{1}{2}(3m)(\frac{1}{3}v_1)^2 = \frac{1}{2}m(\frac{1}{3}v_1^2)[/tex]
Therefore, the ratio of their kinetic energies is
[tex]\dfrac{\Delta KE_2}{\Delta KE_1} = \dfrac{\frac{1}{2}(\frac{1}{3}v_1^2)}{\frac{1}{2}v_1^2} = \dfrac{1}{3}[/tex]
human activities that interfere with distribution of natural resources are contributing to the increase of earthquake risk.
Answer:
Changes in climate conditions, especially the warming of global temperatures increases the likelihood of weather-related natural disasters. ... This is most visible when seen through changes in the intensity and frequency of droughts, storms, floods, extreme temperatures and wildfires.
We say that evaporation is a cooling process. (a) What cools and what warms? We say that condensation is a warming process. (b) What warms and what cools?
Answer:
a liquid warms gas cools
b solid piece warms and liquid cools
A speedometer in a car gives the car’s speed at that given moment, or the?
A. General speed
B. Instantaneous speed
C. Average speed
D. Constant speed
It’s not C or D!
Answer:
a because it is at a given moment
Explanation:
did u
Topic: Physical and Chemical Changes
Subject: Science
Grade: 5th
Question: Why am I growing?
(Please give this answer related to Physical and Chemical Changes.
Answer: Why am I growing is a chemical change.
Explanation:
Changes that can be reversed and does not affect the composition of a substance are called physical changes.
For example, change in state of a substance like ice converting into water is a physical change.
Changes that cannot be reversed and affect the chemical composition of a substance are called chemical changes.
For example, a child growing is an irreversible change and hence, it is a chemical change.
Thus, we can conclude that why am I growing is a chemical change.
What is the main form of energy present in the initial state? (Initial state is when the rubber band is stretched , just before it is released)
O gravitational potential
O kinetic
O thermal
O elastic potential
When you irradiate a metal with light of wavelength 433 nm in an investigation of the photoelectric effect, you discover that a potential difference of 1.43 V is needed to reduce the current to zero. What is the energy of a photon of this light in electron volts? energy of a photon: Find the work function of the irradiated metal in electron volts. work function:
Answer:
The right solution is:
(a) 2.87 eV
(b) 1.4375 eV
Explanation:
Given:
Wavelength,
= 433 nm
Potential difference,
= 1.43 V
Now,
(a)
The energy of photon will be:
E = [tex]\frac{6.626\times 10^{-34}\times 3\times 10^8}{433\times 10^{-9}}[/tex]
= [tex]4.59\times 10^{-19} \ J[/tex]
or,
= [tex]\frac{4.59\times 10^{-19}}{1.6\times 10^{-19}}[/tex]
= [tex]2.87 \ eV[/tex]
(b)
As we know,
⇒ [tex]Vq=\frac{hc}{\lambda}-\Phi_0[/tex]
By substituting the values, we get
⇒ [tex]1.43\times 1.6\times 10^{19}=\frac{6.626\times 10^{-34}\times 3\times 10^8}{433\times 10^{-9}}-\Phi_0[/tex]
⇒ [tex]\Phi_0=2.3\times 10^{-19} \ J[/tex]
or,
⇒ [tex]=\frac{2.3\times 10^{-19}}{1.6\times 10^{-19}}[/tex]
⇒ [tex]=1.4375 \ eV[/tex]
