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.
A race car sits on the starting line on a racetrack. when the race starts, the car's tires exert a force on the track. According to newton's third law of motion, what causes the car to accelerate forward?
A. the track surface exerts a force that is larger and in the same direction as the force exerted by th tires.
B. a normal force that is equal in a magnitude to gravity pushes up on the car
C. the force of friction between the car tires and the track pulls the car forward
D. the track exerts a force that is equal and in the opposite direction as the force exerted by the tires
Answer:
D. the track exerts a force that is equal and in the opposite direction as the force exerted by the tires
Explanation:
Newton's third law of motion states that for every action, there is an equal and opposite reaction. This speaks of equality in magnitude of force applied but in an opposite direction to one another.
According to this reaction, a car's tires exert a force on the track, this means that in accordance to Newton's third law, the track must exert an equal but opposite force on the car's tires. This causes the car to accelerate forward.
A converging lens of focal length 20cm, forms a real image twice the size of the object. Calculate:
i) the power of the lens;
ii) the position of the image.
Answer:
Solition given:
focal length(f)=20cm
size of image(v)=2x
size of object(u)=x
we have
power of lens= reciprocal to focal length=1/20=0.05/cm
ii.
the position of the image is beyond C.
Explanation:
See the attachment !!!!!!!
The question is given in the picture below.... please help me and mention all the steps..
Answer:
a)water is turning into ice it is changing it's state from liquid to solid
b)B to C ice is melting and it is changing it's state from solid to liquid
C to D water is boiling and it is changing it's state from liquid to vapours(steam)
c) temperature
At A 0
At B 0
At C 100
At D 100
Explanation: The temperature will remain 0 degrees Celsius until all the ice becomes water and the temperature will remain 100 degrees Celsius until all the water changes into steam.
Which choice shows the correct sequence of features formed by continued wave erosion?
Answer:
Wave-cut cliff, sea arch, sea stacks
Explanation:
The effect of a wave erosion is made obvious by the structures formed by the wave action.
The high areas of land adjacent to the incoming wave develop the early features or the formation of wave action, which includes the wave-cut cliff
The continuous undercutting of the cliff by the wave results in the formation of the wave cut platform
The effect of the wave further on a cliff, results in the formation of a sea arch and finally a sea stack
Therefore, the correct sequence is the wave-cut cliff, sea arch, sea stacks
A stone is thrown vertically upwards with an initial velocity of 20m/s. Find the maximum height it reaches and the time taken by it to reach the height (g=10m/s).
Answer:
20m in 2 secs
Explanation:
t=2s
s=20m
hence the maximum height reached by stone is 20m in 2 s
The image shows a landform created by Earth’s forces.
A dip in a mountain range between two plates.
Which describes this landform?
anticline
shearing
syncline
tension
The term that best describes the landform "dip in a mountain range" is C. Syncline.
Syncline is a term to refer to a fold of the Earth's crust caused by the tectonic effects of the earth's dynamics. A synclinal fold is characterized by being a concave fold, that is, in the shape of a U.
According to the above, answers A, B and D are not correct options because they refer to different shapes of the Earth. Therefore, the landform shown is syncline.
Learn more at: https://brainly.com/question/17137827
Answer: C
Explanation: E2022
What is the purpose of the lab the importance of the topic and the question you are trying to answer?
perpose of lab is to store apparatus and do some experiment
Helps someone to know the exert lengh of something
If Bulb B burns
out, what happens?
A Bulb A and C will stay lit.
Answer: C
Explanation:
Since bulb B is burnt out, the wires can't transfer to bulb A, so that's why bulb A will burn out.
If I get it wrong, sorry. Im still learning.
If the force on a spring is 2 N and it stretched 0.5 m, what is the spring constant?
O A. 2 N/m
OB. 0.2 N/m
OC. 0.4 N/m
OD. 4 N/m
answer is
0.4n/m3.7 kg of a saturated water vapor at 0.4 MPa is isothermally cooled until it is a saturated liquid. Calculate the amount of heat rejected during this process in MJ. (Report your answer in 3 decimal places.)
Answer:
7.894 MJ
Explanation:
Given that:
The mass of the saturated water vapor = 3.7 kg
The pressure of the saturated water vapor = 0.4 MPa
From saturated properties of steam tables when the pressure is at 0.4 Mpa
The enthalpy in (kJ/kg);
hf = 604.7 kJ/kg
hg = 2738.1 kJ/kg
The rejected heat during this process is:
Q = m(hg - hf)
Q = 3.7(2738.1 - 604.7) kJ/kg
Q = 3.7(2133.4) kJ/kg
Q = 7893.58 kJ/kg
Q = 7.894 MJ
physics as a subject involves measurement and estimation,giving examples of everyday life situations, explain the meaning and what is done in each case
Answer:
57
Explanation:
How Do Manometers Work? steps by steps
Explanation:
A manometer is a device that measures air pressure using a container with a "U"-shaped tube open at one or both ends. In a closed manometer, a sample of gas is introduced into one end, which is then capped. ... This pressure represents the positive or negative difference between the gas pressure and atmospheric pressure
Answer:
I hope this helps In the manometer, one end connects to a gas-tight seal to test the pressure source.2. In addition, the other end of the tube is left open to the atmosphere and it will be subjected to the pressure of approximately 1 atmosphere (atm).
3. Besides, the test pressure is greater than the pressure of 1 atm (atmosphere) the liquid in the column will be forced down by the pressure.
4. Furthermore, it will cause the liquid of the reference column to rise by an equal amount.
-8. A vessel is filled with a 20cm of water. When an irregular body of mass 800gm is immersed the volume of water is increased to 60cm3. What is the density of irregular shaped body?
Answer:
13.33 g/cm3
Explanation:
density = mass/volume
mass of irregular body = 800 grams
new volume = 60 cube cm
= density = 800/60 = 13.333 g/cm3
If we aim a radio telescope at a distant spiral arm of the Milky Way Galaxy, we will probably observe a 21-cm line. If we point a large optical telescope at this same region, we will probably not be able to detect the neutral hydrogen that gives rise to the 21-cm radio signal. Why not
Answer:
Because of the interstellar dust and interior location of the solar system.
Explanation:
We will probably not be able to detect the neutral hydrogen that gives rise to the 21-cm radio signal if we point a large optical telescope to the region because, the interstellar dust obscures the location of the spiral arm of the Milky way galaxy and this makes neutral hydrogen that gives rise to the 21-cm radio signal difficult to detect.
Also, the interior location of the solar system also makes the neutral hydrogen that gives rise to the 21-cm radio signal difficult to detect.
So, the interstellar dust and the interior location of the solar system makes it difficult to detect the neutral hydrogen that gives rise to the 21-cm radio signal with a large optical telescope.
Explain how a submarine
floats on the water surface
and dives down into water.
Answer:
A submarine uses tanks that are filled with compressed air and when it is needed the air is released and takes on water which increase the density making it sink but when the water is pushed out the sub marine density is decreased making it float
John walked a distance of 900 meters in 10 minutes what was his average speed in kilomerters per hour
Answer:
5.4
Explanation:
900/10=90 and 90(60)=5400 meters. 5400/100=5.4
In isoelectric focusing gel electrophoresis a. there is a pH gradient that parallels the electric field gradient b. particular care must be taken to ensure the same pH along the length of the gel c. the electric current is allowed to fluctuate d. the electric circuits of the apparatus must be very well insulated
Answer:
a. there is a pH gradient that parallels the electric field gradient.
Explanation:
Gel electrophoresis is a technique used to separate DNA fragments according to their size. DNA samples are loaded in the wells and then electric current is applied to pull the DNA fragments out from the gel. Isoelectric gel electrophoresis is a process in which negatively charged DNA fragments are separated from the gel.
Describe the laws of liquid pressure and explain the term fluid. (Please try to give the correct answer 'coz it's urgent!)
Answer:
The laws of liquid pressure are: ... The liquid pressure at a point inside the liquid is same in all directions. The liquid pressure at a point inside the liquid is directly proportional to the depth of that point from the free surface of liquid. The pressure of liquid at same depth is different for different liquids
Answer:
The laws of liquid pressure:
The pressure that is inside the liquid rises with the intensity from the surface of a liquid.
The term fluid:
Fluid is basically liquid and a substance that is known to have no certain shape. The opposite of the term fluid would be solid.
Q010) A well in which the water rises on its own to a level above its aquifer Group of answer choices is the result of pressure within a confined aquifer that creates a potentiometric surface. is called an ordinary well. always pushes water higher than the ground surface. cannot be used for commercial or public use, as the water is under too much pressure.
Answer:
The result of pressure within a confined aquifer that creates a potentiometric surface
Explanation:
There are conditions under the Earth's surface, where porous rock layers are tilted and also have a confining, less porous, rock layer about the their boundary, forming a confined aquifer. The existing pressure in the aquifer is therefore confined within the water and the porous rock layer, such that drilling into the pressurized aquifer leads to the water rising under the pressure existing in the aquifer, to a potentiometric surface which is above the actual underground level of the aquifer
A 210 Ohm resistor uses 9.28 W of
power. How much current flows
through the resistor?
(Unit = A)
Current=I
[tex]\boxed{\sf P=I^2R}[/tex]
[tex]\\ \sf\longmapsto I^2=\dfrac{P}{R}[/tex]
[tex]\\ \sf\longmapsto I^2=\dfrac{9.28}{210}[/tex]
[tex]\\ \sf\longmapsto I^2\approx0.04[/tex]
[tex]\\ \sf\longmapsto I\approx\sqrt{0.04}[/tex]
[tex]\\ \sf\longmapsto I\approx\sqrt{\dfrac{4}{100}}[/tex]
[tex]\\ \sf\longmapsto I\approx\dfrac{\sqrt{4}}{\sqrt{100}}[/tex]
[tex]\\ \sf\longmapsto I\approx\dfrac{2}{10}[/tex]
[tex]\\ \sf\longmapsto I\approx0.2A[/tex]
the mass of earth is 6*10^24 and of mars is 6*10^23 and gravitational force is 6.67*10^16 ,find the distance between their centres.
Answer:
6× 10¹⁰ metres
Explanation:
F=(G×M1×M2)/r²
(6.67×10¹⁶)=((6.67×10^-11)(6×10²⁴)(6×10²³))/r²
r²=3.6×10²¹
Therefore r=6×10¹⁰ metres
what will happen to the gravition force between two bodies if the distance between them is halved keeping their masses constant
Answer:
The new force will be 4times the original
A car is traveling at 36km/h when it accelerates and after 2 seconds the car reaches a speed of 54km/h. Calculate the speed of the car in 2s?
An observer measures a 100 Hz Doppler shift as an ambulance goes by. At rest, the frequency of the ambulance's siren is 2,000 Hz. What is the speed of the ambulance?
The change in the frequency of the sound, due to the relative motion of the source of sound and the observer, is determined by the Doppler's Effect.
The speed of the ambulance (source) is "6517 m/s"
The equation of Doppler's Effect is given as follows:
[tex]f_o = \frac{v+v_o}{v+v_s}f_s[/tex]
where,
[tex]f_o\\[/tex] = frequency of sound measure by observer = 100 Hz
v = speed of sound = 343 m/s
[tex]v_o[/tex] = speed of observer = 0 m/s
[tex]v_s[/tex] = speed of ambulance (source) = ?
[tex]f_s[/tex] = actual frequency = 2000 Hz
Therefore, using the values, we get:
[tex]100\ Hz = \frac{343\ m/s + 0\ m/s}{343\ m/s + v_s}(2000\ Hz)\\\\(100\ Hz)(343\ m/s + v_s) = (343\ m/s)(2000\ Hz)\\\\v_s = \frac{686000\ Hz.m/s - 34300\ Hz.m/s}{100\ Hz}[/tex]
v_s = 6517 m/s
Learn more about Doppler's Effect here:
https://brainly.com/question/1330077?referrer=searchResults
7. A thin wire was wound 30 times closely over a boiling tube. The total length of the windings as measured was found to be 6.3mm. Determine the diameter of the wire .
Answer:
Diameter of wire = 0.00021 meters
Explanation:
Given the following data;
Number of windings = 30
Length of windings = 6.3 mm to meters = 0.0063 meters
To find the diameter of the wire, we would use this mathematical expression;
Length of windings = number of windings * diameter of wire
Substituting the values into the expression, we have;
0.0063 = 30 * diameter of wire
Diameter of wire = 0.0063/30
Diameter of wire = 0.00021 meters
how does the siphon work
Answer:
A simple siphon raises water over a crest and discharges it at a lower level.It works coninueasly due to pull of gravity.
Explanation:
Siphons are tubes which draw fluid over the rim of a tank to a lower point. After an initial pressure change to initiate the flow, siphons operate continuously due to the pull of gravity.
Working:
A simple siphon raises water over a crest and discharges it at a lower level. As water flows through a siphon, energy due to pressure and elevation is either lost to pipe friction or converted to velocity energy.
is iron and copper brittle
Answer:
no
Explanation:
they are metal and there property is strong and hard
7. Describe about the difficultites that would arise due to lack of non-uniformity in measurement.
Answer:
Many difficulties would arise if there was a lack of uniformity in the measurement of various weights and measures between business, industry, individuals and countries. The biggest implications for a lack of uniformity are in health and safety, equity and sustainability.
Explanation:
palike nlng po
the hydrometer with the density of liquid to be 800 kg metre per square is the volume of the submerged part of the hydrometer is 5 into 10 to the power minus 5 calculate the mass of the hydrometer
Answer:
Mass = 0.04 Kg
Explanation:
Given the following data;
Density = 800 kg/m³
Volume = 5 * 10^{-5} m³
To find the mass of the object;
Density can be defined as mass all over the volume of an object.
Simply stated, density is mass per unit volume of an object.
Mathematically, density is given by the formula;
[tex] Density = \frac {mass}{volume} [/tex]
Making mass the subject of formula, we have;
[tex] Mass = density * volume [/tex]
Substituting the values into the formula, we have;
[tex] Mass = 800 * 5 * 10^{-5} [/tex]
Mass = 0.04 Kg
a load of 800 newton is lifted by an effort of 200 Newton. if the load is placed at a distance of 10 cm from the fulcrum. what will be the effort distance ?
Answer:
40 cm
Explanation:
We are given that
Load=800 N
Effort=200 N
Load distance=10 cm
We have to find the effort distance.
We know that
[tex]load\times load\;distance=Effort\times effort\;distance[/tex]
Using the formula
[tex]800\times 10=200\times effort\;distance[/tex]
Effort distance=[tex]\frac{800\times 10}{200}[/tex]
Effort distance=[tex]\frac{8000}{200}[/tex]
Effort distance=40 cm
Hence, the effort distance will be 40 cm.
