Answer:
There is not such thing as SI unit of meter
Meter is SI unit for length
Explain why gaps are left between railway lines
Answer:
to prevent the derailing of the train due to thermal expansion.
Answer:
Iron are good conductors of heat and electricity. Being a good conductor it expands as well as contracts with the change of temperature.When heat is applied,they expands because molecules inside the element gets excited and number of molecules inside it increases in tremendous amount,so it leads to expansion of iron. So when the temperature is lowered it comes in its normal state.
The term for this is called as thermal expansion or contraction.The gap in the joint between 2 rails is to prevent from the expansion of the iron. It is necessary ,if not there will be change in structure,it may buckle and chance of derailed is increased.
Explanation:
The gap in the joint between to rails is to compensate for the expansion of the material of rail during summer.
The metals expand or contract with the changes in temperature. The expansion or contraction depends on the coefficient of thermal expansion of the material. Based on this property of the metal, the gap in the joint of two rails is provided.
!!! HELP!!! HELL GELP HELP HELP
Answer:
supernova
Explanation:
Select the correct answer.
The particles in a mechanical wave are moving back and forth in the same direction the wave is traveling in. What’s the shape of the wave?
double transverse
longitudinal
oval-shaped
transverse
Answer: Longitudinal
Explanation:
A bullet was fired from a gun. The bullet had a mass of 50g and the kinetic energy of the bullet was 25 kJ. How fast did it go?
Will give brainliest
Answer:
[tex]given \: \\ mass \: (m) = 50g \\ kinetic \: enegy \: (k.e) = 25kj \\ velocity(v) = x \\ form \\ k.e = \frac{1}{2} \times MV ^{2} \\ 25 = \frac{1}{2} \times 50 \times v {}^{2} \\ 25 = 25 \times v {}^{2} \\ v {}^{2} = \frac{25}{25} \\ v {}^{2} = 1 \\ v = \sqrt{1} \\ v = 1ms {}^{ - } [/tex]
the car it go fast with velocity 1m/s
Rosita started riding her bike 3 km to her friend Gena’s place at exactly the same time Gena started skating to Rosita’s house. Gena, of course, wasn’t home, so Rosita rode back home. The two girls arrived at Rosita’s house at the same time. It took Rosita 30 minutes to ride to Gena’s and back. How fast did Gena skate?
Answer:
6km/hr
Explanation:
Lets make a chart
R. G
D 6km. 6 /2=3km
S. 6/1/1= 12 km/h. 6km/h= 3/1/2
T 1/2hr 1/2hr
so 6km/hr hope that helps if it does please mark as brainliest.
RE (8
10 ms
1. What is the length of the liquid column in a barometer tube that would support an atmospheric pressure of
10,200 Nm2 if the density of the liquid is 2,600 kgm
5 kg dog accelerates at a rate of 3 m/s2. What is the net force acting on the dog?
A. 2 N
B. 15 N
C. 8 N
D. 1.5 N
Answer:
The answer would be C. 8 N
Explanation:
How do longitudinal waves differ from transverse waves? Give examples of both.
Answer:
Explanation:
Longitudinal
The medium moves in the same direction of the wave
It acts in one dimension
The wave cannot be polarized or aligned
This wave can be produced in any medium such as gas, liquid or solid
The earthquake P wave is an example
It is made of rarefactions and compressions
Transverse
The medium is moving perpendicular to the direction of wave
It acts in two dimension
The wave can be polarized or aligned
This wave can be produced in solid and liquid’s surface
Earthquake S wave is an example
It is made of troughs and crests
1.) A projectile is launched at 32.1 m/s and 52.6 º above the horizontal. Determine the:
a.) Maximum height of the projectile.
b.) The time it takes to reach the maximum height
c.) Time of flight
d.) Range
Answer:
a.) Maximum height of the projectile. =32.5m
b.) The time it takes to reach the maximum height=2.6s
c.) Time of flight=2.6s
d.) Range=99.5m
Explanation:
How much energy would be needed for a 100kg body to escape from the earth?radius of earh=6400 km
Answer:
Energy = 6400000 Joules
Explanation:
Given the following data;
Mass = 100kg
Radius of earth = 6400 km
To find the amount of energy required by the object to escape the velocity of the earth, we would apply the Law of Conservation of Energy.
This law 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.
At the earth surface, potential energy with respect to the radius of the earth is given by the formula;
[tex] Ui = - \frac {GM}{R} [/tex] ......equation 2.
Also, at the earth surface, kinetic energy is given by the formula;
[tex] K.E = \frac{1}{2}MV^{2}[/tex] .......equation 3.
After escaping the earth, the object wouldn't have both kinetic and potential energy; Kf = Uf = 0
Substituting eqn 2 & 3 into eqn 1, we have;
[tex] \frac{1}{2}MV^{2} - \frac {GM}{R} = 0 [/tex]
[tex] \frac{1}{2}MV^{2} = \frac {GM}{R} [/tex]
Making "V" the subject of formula;
[tex] RMV^{2} = 2GM [/tex]
[tex] V^{2} = \frac {2GM}{RM} [/tex]
[tex] V^{2} = \frac {2G}{R} [/tex]
Therefore, energy = gmR
Energy = 10 * 100 * 6400
Energy = 6400000 Joules
HELP ASAP PLS
A locomotive with a rocket engine is being tested on a smooth horizontal track. The mass of the
locomotive is unknown. Starting from rest, the engines are fired for 20 s. During this time
they expel 500 kg of oxidized kerosene. The kerosene particles are expelled at an average
velocity of 1200 m/s. At the end of the 20-s period the speed of the locomotive is 50 m/s.
What is its mass?
Answer:
The mass of the locomotive is 288,000 kg
Explanation:
The question relates to the law of conservation of energy
The given parameters are;
The form of engine on the locomotive = Rocket engine
The mass of the locomotive = m
The initial velocity of the locomotive, v = 0 m/s
The duration at which the engine is fired = 20 s
The mass of the kerosene expelled, m₁ = 500 kg
The average speed with which the kerosene is expelled, v₁ = 1,200 m/s
The final speed of the locomotive engine after 20-s, v₂ = 50 m/s
Kinetic energy, K.E. = 1/2·m·v²
The total kinetic energy of the kerosene particles, K.E.[tex]_k[/tex] = 1/2 × 500 × 1,200² = 360,000,000
∴ K.E.[tex]_k[/tex] = 360,000,000 J
By the conservation of energy, the kinetic energy of the expelled kerosene particles is equal to the kinetic energy gained by the moving locomotive
Therefore, we have;
K.E.[tex]_L[/tex] = K.E.[tex]_k[/tex]
K.E.[tex]_L[/tex] = 1/2 × m × v₂² = 1/2 × m × 50²
∴ K.E.[tex]_L[/tex] = 1/2 × m × 50² = K.E.[tex]_k[/tex] = 360,000,000 J
1/2 × m × 50² = 360,000,000 J
m = 360,000,000 J/(1/2 × (50 m/s)²) = 288,000 kg
m = 288,000 kg
The mass of the locomotive, m = 288,000 kg
4. An egg is thrown horizontally off the roof that is 60 meters high, with an initial velocity of
6.5m/s. How long does it take to hit the ground? How far does it go in the x direction?
Answer:
It will take 3.5s to reach the ground
Explanation:
dan is going swimming to get some exercise.which of the following is appropriate swim safety advice?
Answer:
C.
If he is pulled into a current, he should swim toward the shore at a 45-degree angle.
Explanation:
Find the weight of an object of mass 5 kg
on
i. Surface of the earth
ii. b) Surface of the moon
Answer:
weight on earth is mg
which is 5*9.8
49 Newton
weight on moon is 1/6 th of weight on earth
1/6*49
8.166 Newton..
Answer:
1
For instance, on Earth, a 5.0-kg object weighs 49 N; on the Moon, where g is 1.67 m/s2, the object weighs 8.4 N.
2
The weight of the object on the surface of earth would be 5kg. The weight of the object on the surface of moon would be 5/6= 0.83 as the weight of any object on earth is six times than that on moon.
When objects are moved further apart from each other, the force of gravity
A) increases.
B) stays the same.
C) decreases.
D) decreases at first and then increases.
Answer:
The answer to this question is C.
Two forces are acting on an object.
One force is 6 N forward.
The other force is 8 N backward.
What is the net force acting on the object?
- 14 N forward
- 2 N backward
- 2 N forward
Answer:
8N -6N = 2N
Explanation:
opposite forces
Answer:
2N backward
Explanation:
6 - 8 = -2
because there is more force backwards than forwards
Mass of Sun
2.0 x 10^30 kg
Mass lost each second 4.3 × 10^9kg
Lifetime of the Sun left 5 x 10 ^9years
Calculate the percentage of the Sun's mass that will
be converted to energy in the remainder of its
lifetime.
Percentage of mass converted to energy =
Answer:
Percentage of mass converted to energy = 99.9 %
Explanation:
By far most of the solar system's mass is in the Sun itself: somewhere between 99.8 and 99.9 percent. The rest is split between the planets and their satellites, and the comets and asteroids and the dust and gas surrounding our star. Seen from afar (on the scale of distances between stars) the presence of the solar system would not be obvious. We would simply see a normal-looking star. Perhaps we would pick up the presence of Jupiter, which makes up two thirds or so of the solar system outside of the Sun, by mass.
the speed of propagation of seismic waves is about 4km/s an earthquake takes place in Turkey at 13:21:00 the center of the earthquake is at 500km from beirut
at waht time would a seismograph in beiurt rcord the earthquake?
Answer:
14:30:00
Explanation:
because the speed of propagation of seismic waves is at 500
which types of landfrom would you prefer for living?why?
Answer:
Landforms affect where people build houses and communities. Many people live on plains because it is easy to travel and to farm on flat land. Other people live in valleys, which are the land between mountains or hills. The soil in valleys is good for farming.
Answer: lake
Explanation: it would almost always be cool. And cool things are inside!
Mass is a measure of the amount of
matter in a substance. Which of the
following is TRUE about mass?
A. Mass can be measured using a triple beam balance.
B. Mass and volume can be measured using a
graduated cylinder.
C. Mass and length can be measured using a ruler.
D. Mass and temperature can be measured using a
thermometer.
Answer:
A
Explanation:
Can read mass precisely, commonly reading error of +0.05g
Mass is a measure of the amount of matter in a substance. Mass can be measured using a triple beam balance. Hence option (A) is correct.
What is mass?In physics, mass is a quantitative measurement of inertia, a basic characteristic of all matter. It essentially refers to a body of matter's resistance to changing its speed or location in response to the application of a force. The change caused by an applied force is smaller the more mass a body has. The kilograms serves as the unit of mass in the International System of Units (SI).
The conservation of mass principle states that no matter how an object's component pieces are rearranged, the object's overall mass remains constant. If a body splits into parts, the mass also splits into pieces, therefore the original mass is equal to the sum of the masses of the individual fragments. Alternatively, if two or more particles are combined, the mass of the resulting composite equals the total of the masses of the individual particles. This rule is not always accurate, though.
Learn more about mass here:
https://brainly.com/question/19694949
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The combination of all of the forces acting on an object is called the
A) total force.
B) union of forces.
C) super force.
D) net force.
Answer:
The combination of all of the forces acting on an object is called D. net force
Explanation:
Science
Continental Drift is that mountain ranges in
North America line up with mountain ranges in
South America
Europe
Africa
Australia
Most houses in the countries that experience winter have air heaters installed.These heaters are usually installed near the floor.Explain why.
Answer: because the air currents move upwards so the hot air fills up the whole room. Similarly if the air conditioner is placed neer the ceiling because it gives cool air
four equal charges of +3microcolumb are placed at the four corners of a square that is 40cm on a side. Find the force on any one of the charge.
Answer:
i can see your question
pls fast
What resultant force would accelerate an 810kg mass at 6.7 m/s squared?
Answer:
you need to multiply them and then you have your answer eg = 810 × 6.7 = 5427kg
Resultant force would accelerate an 810 kg mass at 6.7 m/s² 5427 N
What is force?A force is an effect that can alter an object's motion according to physics. An object with mass can change its velocity, or accelerate, as a result of a force. An obvious way to describe force is as a push or a pull. A force is a vector quantity since it has both magnitude and direction.
Given in the question,
Acceleration (a) = 6.7 m/s²
Mass (m) = 810 kg
Force (F) = ?
We know
F = M * a
F = 810 * 6.7
F = 5427 N
Resultant force would accelerate an 810 kg mass at 6.7 m/s² 5427 N
To learn more about force refer to the link:
brainly.com/question/13191643
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If energy is used at a rate of 20.0 J/s in an electric
circuit what is the power developed
Answer:
20watts
Explanation:
Formula for calculating power is expressed as;
Power = Work done/Time
Note that the unit of workdone is Joules
Unit of Time is seconds
Hence the unit of power is Joules/seconds or J/s
Hence if the rate at which energy is used up is 20.0J/s, the power will also be 20J/s or 20watts since they have the same unit.
What the energy transformation of an solar panel?
Answer:
The light energy from the sun causes the particles of the object to vibrate, transforming the light energy into heat energy. The heat energy is then radiated out as infrared light.
Explanation:
c) 12g/cm d) 0.2g/cm
6. A girl of mass 40kg wears heels of an area of 1cm2 in contact with the ground,
the pressure on the ground (g=9.8 m/s2)
ad Y10-4na
b) 4x104 na
c) 4 105
da 105
Explanation:
Is this ok?......I have got the answer in pascals.
pls help its due today
What is the velocity of a cup dropped from a building if it takes 8.8 seconds for the cup to hit the ground? (Gravity = -9.8 m/s2).
Answer: vf= 86.24
Explanation:
Basic physics kinematic problem right. So we assume if this is freefall the object or cup in this case is falling with an initial speed of zero and then starts to accelerate due to the force of gravity. First lets see what equations we should use:
Imma use
d=vi+vf/2*t
d=vi*t+ 1/2*a*t^2
First I will solve for distance just to make it easier for me to use the equations.
d= 0(initial speed)*8.8s+1/2*(9.8m/s^2)(8.8)^2 or just d=1/2*(9.8m/s^2)(8.8)^2
d= 379.456
Alright lets use this info in the next equation
379.456= 0 + vf / 2 *8.8 or 379.456= vf/2 *8.8= vf= 86.24m/s
help fast plssssssssssss
Answer:
star
Explanation:
because that is what our sun is.
