Room heaters are placed on the floor of a room so that the air heated by it rises up and sets up the convection current in the room quickly and uniformly.
a.
[2]
A train covers 450 km in 5 hr. between Station A and Station B.
What is the average speed of train in km/h and m/s.
Answer:
90 km/h
50 m/s
Explanation:
Distance = 450 km
Time = 5hrs
Speed = Distance/Time
450/5 = 90 km/h
1 km = 1,000 m
1 hr = 60m = 60 x 60 = 3,600 sec
but since it's 5hrs = 60 x 300m = 18,000
90 x 1,000 = 90,000/18,000 = 50 m/s
The Indianapolis speedway consists of a 2.5 mile track having four turns, each 0.25 mile long and banked at 9 12'
Answer: Your question is missing below is the question
Question : What is the no-friction needed speed (in m/s ) for these turns?
answer:
20.1 m/s
Explanation:
2.5 mile track
number of turns = 4
length of each turn = 0.25 mile
banked at 9 12'
Determine the no-friction needed speed
First step : calculate the value of R
2πR / 4 = πR / 2
note : πR / 2 = 0.25 mile
∴ R = ( 0.25 * 2 ) / π
= 0.159 mile ≈ 256 m
Finally no-friction needed speed
tan θ = v^2 / gR
∴ v^2 = gR * tan θ
v = √9.81 * 256 * tan(9.2°) = 20.1 m/s
A wire, 20m long, is heated from a temperature of 5°C to 55°C. If the change in length is 0.020m, calculate the linear expansivity of the wire.
Answer:
0.01998⁰C;¹
Explanation:
you can see all steps in photo
A pendulum, like a bobblehead, moves back and forth through a resting position. At what point on its path is the net force acting on the pendulum zero?
Group of answer choices
When the pendulum is displaced as far to the left as it can be.
When the pendulum is displaced as far to the right as it can be.
When the pendulum is at its resting position.
Never…there is always a net force acting on a pendulum
Answer:
[tex]\\ \longrightarrow\:\bf \purple{\dfrac{1}{v} = \dfrac{1}{ - 100} + \:\dfrac{1}{20} }[/tex]
A bullet from a gun at 30° to the horizontal remains in flight for 25s before touching the ground.Calculate the velocity of the projection.
Answer: The velocity of the bullet will be more than half of its earlier velocity
Explanation: I did it on a test and it was right because i calculated 30 degrees within 25 seconds and it was half times the velocity
i hope this helps sorry if i got it wrong
What's Alpha beta gamma emission??
If the mass of the Jupiter is 1.9*10 kg and radius is fbx loom what is acclerallon due to gravity on the supiter ?
Answer:
[tex]g=25.92\ m/s^2[/tex]
Explanation:
Given that,
The mass of the Jupiter,[tex]M=1.9\times 10^{27}\ kg[/tex]
The radius of Jupiter,[tex]r=69,911\ km=69911\times 10^3 km[/tex]
We need to find the acceleration due to gravity on Jupiter. The formula is
[tex]g=G\dfrac{M}{r^2}[/tex]
Put all the values,
[tex]g=6.67\times 10^{-11}\times \dfrac{1.9\times 10^{27}}{(69911\times 10^3)^2}\\\\g=25.92\ m/s^2[/tex]
So, the value of acceleration due to gravity on the Jupiter is [tex]25.92\ m/s^2[/tex].
A blackbody radiator was expected to give off energy of increasing frequency
as its temperature increased. Which of the following ideas provided an
important step toward understanding why this was not observed?
A. Light is quantized and must be absorbed as a unit.
B. Electrons can act as both waves and particles.
C. Matter is quantized and cannot be broken down.
D. Large objects can be viewed as acting as waves.
Answer:
B.
Explanation:
Makes more sense to me
How would you find the resistance of a parallel circuit with n identical resistors?
9514 1404 393
Answer:
R/n
Explanation:
For a given voltage V across each resistor R, the current is V/R. Since there are n parallel paths, the total current is n(V/R). The effective resistance is ...
Reff = V/I = V/(nV/R)
Reff = R/n
Mike lives in the northern United States minnesota and nick lives in the southern United States Louisiana. When they both feel insulted by the same individual, nick will be more
Complete question is;
Mike lives in the northern United States (in Minnesota) and Nick lives in the southern United States (Louisiana). When they both feel insulted by the same individual, Nick will be more likely to have a(n) ________ cortisol response and show ________ levels of physical aggression.
Answer:
- A hyper cortisol response
- higher levels of physical aggression
Explanation:
In study of hormones in the human body, it has been discovered that cortisol is a stress inducing hormone. Now, if they are in the summer when it is hot, it has been proven that's when the cortisol hormone circulates in a very large manner in the blood. This leads to frustration and as well possibly physical aggression.
Nick will be more likely to have a(n) hyper cortisol response and show higher levels of physical aggression.
What is cortisol?Cortisol has been identified as a stress-inducing hormone in studies of hormones in the human body.
Mike lives in the northern United States (in Minnesota) and Nick lives in the southern United States (Louisiana).
When they both feel insulted by the same individual, Nick will be more likely to have a(n) hyper cortisol response and show higher levels of physical aggression.
Cushing syndrome is a condition characterized by elevated cortisol levels. This disorder is caused by your body producing too much cortisol.
Similar symptoms can occur after large doses of corticosteroids, thus this should be cleared out before testing for crushing syndrome.
Cortisol has been identified as a stress-inducing hormone in studies of hormones in the human body. Now, if they are in the summer when it is hot.
It has been proved that the cortisol hormone circulates in the blood in a very significant amount. This causes irritation and, in some cases, physical aggressiveness.
Hence nick will be more likely to have a(n) hyper cortisol response and show higher levels of physical aggression.
To learn more about cortisol refer to the link
https://brainly.com/question/7519944
If the density of a substance is 5g/cm3 and the volume is 10cm3,
determine the mass.
Answer:
(5g/cm³)*(10cm³) = 50g
Explanation:
This is just a conversion formula. Easy to find using dimensional analysis.
(5g/cm³)*(10cm³) = 50g
Answer:
[tex]\boxed {\boxed {\sf 50 \ grams}}[/tex]
Explanation:
Density is the amount of mass per unit volume, so the formula is:
[tex]d = \frac{m}{v}[/tex]
The density of the substance is 5 grams per cubic centimeter and the volume is 10 cubic centimeters.
d= 5 g/cm³ v= 10 cm³Substitute the values into the formula.
[tex]5 g/cm^3 = \frac{m}{10 \ cm^3}[/tex]
We are solving for the mass, so we have to isolate the variable m. It is being divided by 10 cubic centimeters. The inverse of division is multiplication, so we multiply both sides of the equation by 10 cm³.
[tex]10 \ cm^3 *5 g/cm^3 = \frac{m}{10 \ cm^3} * 10 \ cm^3[/tex]
[tex]10 \ cm^3 *5 g/cm^3 = m[/tex]
The units of cubic centimeters (cm³) cancel.
[tex]10 *5 g = m[/tex]
[tex]50 \ g=m[/tex]
The mass of the substance is 50 grams.
UNA MASA DE 0,5 KG ESTA SOBRE UNA PENDIENTE SUJETA MEDIANTE UNA CUERDA QUE IMPIDE UN DESLICE. ¿QUE FUERZA HACE LA CUERDA?
Answer:
Tension force acts along the inclined plane.
Explanation:
A MASS OF 0.5 KG IS ON A SLOPE FASTENED BY A ROPE THAT PREVENTS SLIDING. WHAT FORCE DOES THE ROPE MAKE?
A mass of 0.5 kg is fastened on a slope. So there are the two components of weight.
m g sin A acts along the plane in the downwards direction.
m g cos A acts perpendicular to the plane in upwards direction.
The force which acts of the rope as the mass is fastened is the tension force on the rope.
So, the tension force is there.
Can someone pleassse help me
Answer:
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why solid keep their shape?
Answer:
Solids can hold their shape because their molecules are tightly packed together. ... Atoms and molecules in liquids and gases are bouncing and floating around, free to move where they want. The molecules in a solid are stuck in a specific structure or arrangement of atoms
Hope this helps ☆*:. o(≧▽≦)o .:*☆
I don't know how to answer this question, can someone pls help?
- Explain how a wave can transmit energy to a medium without transporting matter.
Thank you for your time!
Answer:
Consider the energy the earth receives from the sun. The electromagnetic waves travel thru empty space until they interact with some medium surrounding the earth: ozone, atmosphere, solids, etc.
This is contrasted to longitudinal waves such as sound waves which can only travel thru the medium with which they interact.
The primary circuit of a transformer has a voltage of 80 V and 300 windings. The secondary circuit has a voltage of 240. How many windings are there in the secondary circuit? *
Answer:
900 windings
Explanation:
Applying,
Vs/Vp = Ns/Np............. Equation 1
Where Vs = Secondary voltage, Vp = primary voltage, Ns = Number of turns in the secondary circuit, Np = number of turns in the primary circuit
make Ns the subject of the equation
Ns = VsNp/Vp........... Equation 2
From the question,
Given: Vs = 240 V, Np = 300 windings, Vp = 80 V
Substitute these values into equation 2
Ns = (240×300)/80
Ns = 900 windings
A convex mirror of radius of curvature 1.6 m has an object placed at a distance of 1.0 m from it. Find the position of image and the magnification.
Answer:
The image is formed at 0.44 m in front of the mirror
magnification (M) = 0.44
Explanation:
Applying, mirror formular
1/f = (1/u)+(1/v).................... Equation 1
Where f = Focal length of the convex mirror, u = object distance, v = image distance.
Using the real is positive convection,
From the question,
Given: f = -1.6/2 = -0.8 m( The focal length of a convex mirror is vitual), u = 1.0 m
Substitute these values into equation 1
-1/0.8 = (1/v)+(1/1)
Solve for v
1/v = 1.25+1
1/v = 2.25
v = 1/2.25
v = 0.44 m
Hence the image is formed at 0.44 m in front of the mirror
Magnification (M) = v/u
m = 0.44/1
m = 0.44
Find the magnetic force experienced by a proton moving with the speed of 4x10^5 m/s in the magnetic field B of magnetic 7x10^-5 T.
A- Fmagnetic = 24.8x10^-19 N
B- Fmagnetic = 34.8x10^-19 N
C- Fmagnetic = 44.8x10^-19 N
D- Fmagnetic = 54.8x10^-19 N
Answer:
F = q v B where B is the component of the field perpendicular to v.
F = 1.6E-19 * 4E5 * 7E-5 = 4.48* 10^-18 N = 44.8 * E-19 N
Solve this question for 5 points
Answer:
M_b = 2M_a
Explanation:
From gravity equation, we know that;
g = GM/R²
Where;
g is acceleration due to gravity
G is the gravitational constant
M is mass
Thus, making mass(M) the subject, we have;
M = gR²/G
Since we want to find the mass of B so that value of g on B is half that of its value on A.
Thus;
> g_b = ½g_a
> g_b/g_a = ½
Also, we are told that;
> R_a = ½R_b
> R_b/R_a = 2
If M_a = g_a•R_a²/G
And M_b = g_b•R_b²/G
Thus;
M_b/M_a = (g_b•R_b²/G)/(g_a•R_a²/G)
G will cancel out to give;
M_b/M_a = (g_b•R_b²)/(g_a•R_a²)
Rearranging for ease of simplification, we have;
M_b/M_a = (g_b/g_a) × (R_b/R_a)²
Plugging in the relevant ratios gives;
M_b/M_a = ½ × 2²
M_b/M_a = 2
M_b = 2M_a
A basketball is shot by a player at a height of 2.0 m. The initial angle
was 53° above horizontal. At the highest point the ball was travelling 6
m/s. If he scored (the ball went through the rim that is 3.00 m above the
ground), what was the player’s horizontal distance from the basket?
Answer:
The answer is "8.28 m".
Explanation:
[tex]\to u \cos 53^{\circ}=6 \ \text{therefore the horizontal velocity is constant alaways}\\\\\therefore[/tex]
[tex]u= \frac{6 \times 5}{3}= \frac{30}{3}= 10\ \frac{m}{s}\\\\[/tex]
In the projectfile when vertical displacement is 1 then 5 m comes at farther sides
Using
[tex]S=ut-\frac{1}{2} gt^2\\\\1=u\sin 53^{\circ}\times t-5t^2\\\\1=8t-5t^2\\\\5t^2-8t+1=0\\\\ t=\frac{8\pm \sqrt{64-20}}{10} \\\\=\frac{8\pm 2\sqrt{11}}{10} \\\\t_2=\frac{8+2\sqrt{11}}{10} \\\\[/tex]
[tex]Distance=u \cos 53^{\circ}\times t_2\\\\[/tex]
[tex]=6 \times \frac{8\pm 2\sqrt{11}}{10} \\\\=\frac{24\pm 6\sqrt{11}}{5} \\\\= 8.28 \ m[/tex]
Cuando una persona sube y baja una escalera, Cuanto vale su desplazamiento y cual es la medida de su trayectoria.
Answer:
Primero, definimos el desplazamiento como la distancia entre la posición final y la posición inicial.
Así, si comenzamos abajo, luego subimos la escalera, y luego bajamos, la posición final y la posición inicial serán la misma
por lo que el desplazamiento es igual a cero.
La medida recorrida es el espacio total recorrido.
Es decir, si entre el principio y el final de la escalera hay una distancia D.
La persona que sube y baja, recorre esta distancia dos veces.
Entonces cuando una persona sube y baja la escalera, la medida de su trayectoria será 2*D.
Tarzan swings back and forth on a
vine with a period of 7.27 s. How
long is the vine?
(Unit = m)
8CM I suppose because he swings and goes to the next vine
A mother is pulling a sled at constant velocity by means of a rope at 37°. The tension on the rope is 120 N. Mass of children plus sled is 55 kg. The mother has a mass of 61 kg.
a) Draw FBD for the sled with the kids as one object
b) Draw FBD for the mother
c) Find the normal force on the sled and on the mother
d) Find the kinetic friction acting on the sled and the static friction acting on the mother
e) Find the coefficient of kinetic friction for the sled
Answer:
Please find the complete solution in the attached file.
Explanation:
2. A cinder block is sitting on a platform 20 m high. It weighs 16kg. The block has
_ joules of potential energy.
Answer:
3136 Joules
Explanation:
Applying,
P.E = mgh.............. Equation 1
Where P.E = potential energy, m = mass of the cinder block, h = height of the platform, g = acceleration due to gravity.
From the question,
Given: m = 16 kg, h = 20 m
Constant: g = 9.8 m/s²
Substitute these values into equation 1
P.E = 16(20)(9.8)
P.E = 3136 Joules
Hence the potential energy of the cinder block is 3136 Joules
An upright image which reduced in size 10 times occurred in a mirror. If the radius of
curvature of the mirror is 2 m, bow far is the object from the mirror?
Answer:
-10/9 m
Explanation:
Radius of curvature, R=2 m
Focal length of mirror, f=R/2=2/2=1 m
Let height of object=h
Height of image, h'=h-10h=-9h
We have to find the distance of object from the mirror.
Magnification, m= [tex]\frac{h'}{h}=-\frac{v}{u}[/tex]
[tex]m=\frac{-9h}{h}=-9[/tex]
Image is upright and small in size it means the mirror is convex.
Focal length of convex mirror is negative.
f=-1m
[tex]-9=-\frac{v}{u}[/tex]
[tex]v=9u[/tex]
Now, mirror formula
[tex]\frac{1}{v}+\frac{1}{u}=-\frac{1}{f}[/tex]
[tex]\frac{1}{9u}+\frac{1}{u}=\frac{1}{1}[/tex]
[tex]\frac{1+9}{9u}=-1[/tex]
[tex]10=-9u[/tex]
[tex]u=-\frac{10}{9} m[/tex]
Hence, the distance of object from the mirror is -10/9 m
why does the green colour of iron (ii) chloride change to yellow when chlorine gas is bubbled into it
Answer:
FeCl2 has a high melting point.
Explanation:
Iron is seen to get oxidized by addition of chlorine 3 as the product is rust colored and on dissolving in water has a yellow orange color. This is characterized by the aquatic iron and is due to the monohydroxyradiation is the main way of transferring heat in a vacuum b solid c gas d liquid
Answer:
gas
................
Explanation:
hope it helps u
When 100.0 mL of ethyl alcohol is heated from 10.0 C to 35.0 C, about how much thermal energy
is absorbed by the ethyl alcohol? (Assume the density of ethyl alcohol to be 0.790 g/mL.)
Answer:
Q = 194.34 J
Explanation:
Given that,
100.0 mL of ethyl alcohol is heated from 10.0 C to 35.0 C.
We need to find the amount of thermal energy absorbed by the ethyl alcohol.
The density of ethyl alcohol is 0.790 g/mL.
The formula for heat absorbed is given by :
[tex]Q=mc\Delta T\\\\As, d=\dfrac{m}{V}\\\\So,\\Q=dVc\Delta T\\\\Q=0.79\times 100\times 2.46\\\\Q=194.34\ J[/tex]
So, 194.34 J of thermal energy is absorbed by the ethyl alcohol.
The study of heat transformation into other forms of energy is called
Answer:
Thermodynamics.
Explanation:
Thermodynamics can be defined as the study of heat transformation into other forms of energy.
Conduction involves the transfer of electric charge or thermal energy due to the movement of particles.
Generally, when conduction relates to electric charge, it is known as electrical conduction while when it relates to thermal energy, it is known as heat conduction.
In the process of heat conduction, thermal energy is usually transferred from fast moving particles to slow moving particles during the collision of these particles. Also, thermal energy is typically transferred between objects that has different degrees of temperature and materials (particles) that are directly in contact with each other but differ in their ability to accept or give up electrons.
In Thermodynamics, heat are generally transformed to various forms of energy such as light energy.
The Law of Conservation of Energy states that energy cannot be destroyed but can only be converted or transformed from one form to another. Therefore, the sum of the initial kinetic energy and potential energy is equal to the sum of the final kinetic energy and potential energy.
Mathematically, it is given by the formula;
Ki + Ui = Kf + Uf .......equation 1
Where;
Ki and Kf are the initial and final kinetic energy respectively.
Ui and Uf are the initial and final potential energy respectively.
Additionally, the Law of Conservation of Energy is another way to describe the First Law of Thermodynamics and it states that the change of the internal energy of a system is equal to the sum of work and heat spent on it.
Mathematically, the First Law of Thermodynamics is given by the formula;
ΔU = Q − W
Where;
ΔU represents the change in internal energy of a system.
Q represents the net heat transfer in and out of the system.
W represents the sum of work (net work) done on or by the system.
Which group of people was most directly affected by the twenty sixth amendment
