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.
Need help as fast as possible please
I will mark BRAINLIST only for correct answers babes :)
Thank you!
Answer:
1) Image
2) virtual
i hope its right ! :)
Explanation:
SOS: I completely forgot what net force is...
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:
The type of energy that a moving object has that increases when the speed of that object increases and is called ____.
Answer:
no
Explanation:
Answer:
The answer is Kinetic Energy.
Explanation:
Kinetic energy basically means energy of mass that's in motion.
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
Question 7 of 10
Which observation is evidence of refraction in this photo?
A. The top of the man's head appears disconnected from the rest of
his head.
B. The man's arm is clearly seen under the water.
C. The snorkel in the man's mouth appears yellow.
a
D. The water in which the man is swimming is transparent.
Answer: it is A
Explanation: A p e c
A protein-digesting enzyme when mixed with starch solution would
Answer:
It would produce fat..........
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:
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
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.
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.
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:
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
what do you call a material which is capable of reducing friction when applied between moving parts?
Answer:
The material is called a Lubricant.
Hope it helps! ☺️
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
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:
which of the following instrument measure time most accurately
a pendulum clock
b sundial
c quartz watches
d sand clock
A saw becomes warm when it is used to cut a log of wood.Give reason
Explanation:
a part of the kinetic energy of the sun is converted into heat as it cuts the log of wood it is due to this heat that becomes worm .Thus, kinetic energy of such changes into heat
Energy in an ecosystem's energy pyramid always flows from __________.
A. decomposers to producers
B. producers to consumers
C. consumers to producers
D. decomposers to consumers
The Answer is B because primary consumers need to get their food from plants.
Answer:
The Answer is B because primary consumers need to get their food from plants
Explanation:
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
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
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:
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:
Can someone help with this? (Picture above)
Answer:
Element #1
protons = 1
neutrons = 0
electrons = 1
atomic number = 1
atomic mass = 1
Element #2
protons = 2
neutrons = 2
electrons = 2
atomic number = 2
atomic mass = 4
Element #3
protons = 3
neutrons = 3
electrons = 3
atomic number = 3
atomic mass = 6
Explanation:
Atomic mass = proton = electrons at neutral state
please give me brainliest if my answer is helpful
An incident ray traveling in a slower medium strikes a boundary with a faster medium. What happens when its angle of incidence is greater than the critical angle?
A.
The refracted ray makes an angle of 90°.
B.
There is total internal reflection in the faster medium.
C.
There is total internal reflection in the slower medium.
D.
The reflected ray makes an angle of 90°.
E.
The reflected ray makes an angle equal to the critical angle.
Answer:
D. The reflected ray makes an angle of 90°.
Explanation:
describe briefly the potential energy it has ( roller coaster)
Answer:
The energy that it starts with at the top of the inclinede Plane
Explanation:
Hope I helped:)
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
how gumamela reproduced
8. If Bulb 8 burns out, how will the remaining bulbs be affected?
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