Answer:
1.) Momentum = 10 units
2.) Because of gravity
Explanation:
According to the Newton 3rd law of motion, we realise that in collision, momentum is always conserved.
So, if a ball is thrown upward with ten units of momentum initially, the “recoil” momentum of the earth will be approximately 10 units of momentum. We do not feel this because of the gravity.
A man of mass 60kg climbs up a 20m long staircase to the top of building 10m high. What is the work done by him
Answer:
mass=60kg
h=20m
g=10m/s²
here the work done by the body is equal to its potential energy
work done=P.E.
As we know that P.E.=mgh
putting values
P.E.=60kg×20m×10m/s²
P.E.=1200kgm×10m/s²
P.E.=12000Nm
so the work done by the body is 12000Nm
Different types of waves travel at different speeds. For example, sound waves travel more slowly than light waves. Have you ever been in a big empty room, or in a cave, and heard an echo? Echos happen because sound waves take time to travel to the wall and bounce back to your ears. But light is different. Light is much faster than sound. Light is the fastest moving thing in the universe. Because light waves and sound waves travel at different speeds, you can figure out how far you are from a storm by watching for lightning and listening for thunder. Lightning and thunder are actually the same thing! Thunder is just the sound that lightning makes. Because light is so quick, you see the lightning flash first. The sound travels more slowly, so you hear the thunder after. Thunder and lightning represent two kinds of waves: sound and light.
How do lightning and thunder illustrate the relationship between light and sound waves?
A Light moves faster than sound, so you hear thunder after you see lightning.
B Sound moves faster than light, so you see lightning after you hear thunder.
C Lightning and thunder are the same, so light and sound waves move together at the same time.
D Sound moves light, so when you hear thunder you know lightning will move toward you.
Answer:
A). Light moves faster than sound, so you hear thunder after you see lightning.
Explanation:
The lightning and thunder demonstrate that 'light travels faster than sound' which clearly portrays the relationship between the light and the soundwaves. When we see lightning in the sky before hearing the sound of thunder as the speed of light much higher than the speed of sound. Sound travels ~ 343 m/s or 1235 km/hr while light travels 300000 km/s. This difference in speed prevents us from considering lightning and thunder as the same thing. The 'sound is a pressure wave and therefore, takes time to travel and bounce back to our ears.' Thus, we happen to witness lightning first. Hence, option A is the correct answer.
A helicopter travels west at 80 mph. It is moving above a car traveling on a highway at 80 mph. Given this information, you can determine that the helicopter and car are traveling ____.
Select one:
a. in the same direction
b. in different directions
c. at the same speed
d. at the same velocity
Answer:
d. at the same velocity
Explanation:
I will assume the car is also travelling westward because it was stated that the helicopter was moving above the car. In that case, it depends where the observer is. If the observer is in the car, the helicopter would look like it is standing still ( because both objects have the same velocity). If the observer is on the side of the road, both objects would be travelling at the same velocity. Also recall that, velocity is a vector quantity; it is direction-aware. Velocity is the rate at which the position changes but speed is the rate at which object covers distance and it is not direction wise. Hence velocity is the best option.
Answer:
C. At the same speed
Explanation:
I just took the exam and got the answer correct
I WILL CHOOSE YOU AS BRAINLIEST
Use scientific evidence to outline how the Big bang theory can be used to explain the origin of the universe and its age.
Answer:
The widely accepted theory for the origin and evolution of the universe is the Big Bang model, which states that the universe began as an incredibly hot, dense point roughly 13.7 billion years ago.
Two bumper cars collide and then move away from each other. The forces exerted are:
A. Equal and opposite
B. Opposite
C. Equal
Answer:
the answer is b
Explanation:
if it was equal they would move away from each other
7. How does friction affect the kinetic energy of an object?
Answer:
Friction is a resistive force to motion. When two bodies move against each other some of the kinetic energy is converted to heat energy due to friction. This reduces the total kinetic energy in the system. ... Mechanical energy is reduced due to friction and converted to heat.
Explanation:
Kinetic friction does oppose the relative motion of two surfaces. If the one of these surfaces is stationary, then it will tend to slow down the moving object.
Calculate the wavelength of an electron mass 9.1*10^-31kg moving with a velocity of 2.0*10^6m/s (h=6.63*10^-34Js) (Hint: De Broglie's wavelength)
Answer:
Wavelength, [tex]\lambda=3.64\times 10^{-10}\ m[/tex]
Explanation:
We have,
Velocity an electron is [tex]2\times 10^6\ m/s[/tex]
Mass of an electron is [tex]9.1\times 10^{-31}\ kg[/tex]
It is required to find the wavelength of electron. The De-Broglie wavelength of an electron is given by :
[tex]\lambda=\dfrac{h}{mv}[/tex]
h is Planck's constant
[tex]\lambda=\dfrac{6.63\times 10^{-34}}{9.1\times 10^{-31}\times 2\times 10^6}\\\\\lambda=3.64\times 10^{-10}\ m[/tex]
So, the wavelength of an electron is [tex]3.64\times 10^{-10}\ m[/tex].
how does the direction of acceleration compare with the direction of the net force that produces it
Answer:
Explanation:
The direction of the acceleration is in the same direction as the net force causing it. F = ma is actually a vector equation in which f and a are both vectors and m is a scalar constant.
If you have two waves, one with a frequency of 4.4 x 1010 Hz and one with a frequency of 3.6 x 1014 Hz, which has the highest energy? Justify your answer
with evidence from the lesson and/or mathematically.
Answer: frequency of 3.6 x 10^14 Hz
Explanation:
If someone have two waves, one with a frequency of 4.4 x 1010 Hz and one with a frequency of 3.6 x 1014 Hz, the one with higher frequency ( 3.6 × 10^14) will have the higher energy.
From electromagnetic spectrum,
E = hf
Where
E = energy
F = frequency
h = Planck constant
The one with higher frequency will have the higher energy since energy is directly proportional to the frequency.
The one with higher frequency ( 3.6 × 10^14) will have the highest energy.
What is the frequency?Frequency is the number of oscillations per second in the sinusoidal wave.
If someone have two waves, one with a frequency of 4.4 x 10¹⁰ Hz and one with a frequency of 3.6 x 10¹⁴ Hz.
From electromagnetic spectrum, energy associated with the frequency is
E = hf
Where, E = energy, f = frequency and h = Planck constant
The Planck's constant is the constant value. The energy is directly proportional to the frequency.
Thus, The one with higher frequency will have the higher energy since energy is directly proportional to the frequency.
Learn more about frequency.
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Question 5(Multiple Choice Worth 4 points) (01.04 MC) Which of the following correctly describes the relationship between speed and velocity? Speed is the change in velocity over time; velocity is distance plus direction. Speed is the change in distance over time; velocity is speed plus direction. Speed is distance plus direction; velocity is speed plus time. Speed is the change in acceleration; velocity is distance over time.
Answer:
Speed is the change in distance over time; velocity is speed plus directionExplanation:
Speed is defined as the change in distance covered by a body with respect to time while velocity the change in displacement of a body with respect to time. Speed is a scalar quantity since it does not specifies direction while velocity is a vector quantity because it specifies both magnitude and direction.
Speed can only be equal to the velocity if it also specifies direction.
Based on the definition above, it can be concluded that speed is the change in distance over time and velocity is speed plus direction.
Answer:
Speed is the change in distance over time; velocity is speed plus direction.
Explanation:
I did it and got the test right
How does the electric force between two charged objects change when the
distance between the objects increases?
Answer:
When the electric force between two charged objects change, the distance between the objects increases in Iicreasing the separation distance between objects and decreases the force of attraction or repulsion between objects.
Hope it helps.
:What will be the value of the refractive index of the medium? Critical angle of that medium is 30 degree
a) 2
b) 1.5
c) 1.8
d) 1
Answer:
Let the second medium be air (n₁=1)
The refractive index n₂ of the medium where first medium is air is found (a)
(a) n₂ = 2
Explanation:
Critical angle can be defined as the angle of incidence that provides the angle of refraction of 90°.
Refractive index of a medium can be defined as a number that describes that how fast a light will travel through that medium.
Critical angle and Refractive index are related by:
[tex]\theta_{critical}= sin^{-1}(\frac{n_1}{n_2})[/tex]
[tex]sin \theta_{critical}=\frac{n_1}{n_2}[/tex]
To find refractive index of medium with respect to air, substitute n₁=1 (Refractive index of air is 1)
Also θ(critical)=30°
Find n₂ :
[tex]sin30= \frac{1}{n_2}\\0.5=\frac{1}{n_2}\\n_2=\frac{1}{0.5}\\n_2=2[/tex]
Liam is two-years old. His mother is concerned about his behavior. Liam is very different from how his sister Briana was when she was his age. He does not make eye contact. When she smiles at him, he doesn’t smile back. He doesn’t seem to like her hugging or kissing him. It seems that Liam has
Answer:
Autism
Explanation:
Those are some symptoms of autism that you described
Answer:
Autism is the answer
describe what factors can make it difficult to reintroduce captive animals into their natural habitats.
Answer:
Captive animals are animals that are maintained by people in an enclosed place not allowing them to be free. There are several factors that make it difficult to reintroduce them to their natural habitats like:
-Captive animals don't learn the necessary skills to survive in their natural habitats like hunting skills.
-They are too used to have contact with people which makes them vulnerable to hunters.
-Sometimes these animals are not able to integrate with a wild population.
-It has been found that some captive animals are more susceptible to diseases.
Someone please help me with this
1. A guitar string vibrates with a frequency of 100 Hz and it has a wavelength of 3 cm. Determine the speed of the wave that goes through that guitar string.
2. The speed of sound waves in air is around 340 m/s. Suppose that you hear a dog growl, and the frequency of the growl is 70 Hz. Determine the wavelength of the growl sound waves.
3. You are in a boat on the ocean. Some waves come by and you feel your boat move up and down. You whip out a stopwatch and find that you go up-and-down once every 5 seconds. So, the period of the wave is 5 s. You are watching the waves as you go up-and-down, and you see that the wave crests are 15 meters apart. So, the wavelength is 15 m. Use this information to calculate the speed of the waves.
4. Explain why these two waves have the same speed, even though some of their wave properties are different.
Wave A has a frequency of 3 Hz and a wavelength of 5 m
Wave B has a frequency of 6 Hz and a wavelength of 2.5 m
Answer: I think 1 is 300 metres per second.
Explanation: wave speed= wave length x wave frequency
wave speed = 3 x 100
wave speed is 300 m/s
Electric circuit questions,,, plz help me
When waves travel through water, why do the moving water particles continue to return to their starting position?
OA.
Waves transfer matter, but not energy.
Waves transfer both matter and energy.
OC.
Waves transfer energy, but not matter.
OD.
Waves don't transfer matter or energy.
Answer:
Waves transfer energy, not matter
Explanation:
Identify the clean sources of energy.
Answer:
biomass, geothermal, hydropower, solar, and wind.
hope this helped!
6. How is work related to kinetic energy?
Answer: Energy should be transferred to an object in order to move it. This amount of energy transferred by the force to move an object is called work or work done. Thus, the relation between Work and Energy is direct. That is, the difference in the Kinetic energy of an object is work done by an object. OR
The principle of work and kinetic energy (also known as the work-energy theorem) states that the work done by the sum of all forces acting on a particle equals the change in the kinetic energy of the particle. The kinetic energy of the block increases as a result by the amount of work.
Explanation:
A wooden object (conically shaped) has a diameter of 8cm and height of 14cm. It floats in oil with 6cm of its height above oil level. Determine (a)The density of the object (b) If the volume of oil is twice that of the object, what fraction of oil is displaced after immersing the object?
Answer:
(a) The density of the object is 316/343 × the density of the oil
(b) The fraction of oil displaced after immersing the object is 0.461 of the oil volume
Explanation:
(a) The volume, V of a cone of height, h and base diameter, D = 2×r is given by the following equation;
[tex]V = \dfrac{\pi r^{2} h}{3}[/tex]
The volume of the object is therefore;
[tex]\dfrac{\pi \times 4^{2} \times 14}{3} = 74\tfrac{2}{3}\pi \, cm^3[/tex]
Where 6 cm is above the oil level we have;
[tex]\dfrac{\pi \times \left (6 \times \dfrac{4}{14} \right )^{2} \times 6}{3} = 5\tfrac{43}{49}\pi \, cm^3[/tex] above the oil level
Therefore, volume of the oil displaced = [tex]68\tfrac{116}{147}\pi[/tex] cm³ = 216.11 cm³
The density of the object is thus;
[tex]\dfrac{68\tfrac{116}{147}\pi}{ 74\tfrac{2}{3}\pi} \times Density \ of \ the \ oil = \dfrac{316}{343} \right ) \times Density \ of \ the \ oil[/tex]
The density of the object = 316/343 × the density of the oil.
(b) The volume of the oil = 2 × Volume of the object = [tex]2 \times 74\tfrac{2}{3}\pi \, cm^3 = 149\tfrac{1}{3}\pi \, cm^3[/tex]
The fraction of the volume displaced, x, after immersing the object is given as follows;
[tex]x = \dfrac{68\tfrac{116}{147}\pi}{ 149\tfrac{1}{3}\pi} = \dfrac{158}{343} = 0.461[/tex]
The fraction of oil displaced after immersing the object = 0.461 of the volume of the oil
can someone help m e
Answer:
A.when the distance is very close from the source
Explanation:
Answerwhen the distance is very close from the source
Explanation: A
In order to increase the speed in a gear system
the driven gear must be larger than the driving gear
the driving gear must be larger than the driven gear
the driving gear must be the same size as the driven gear
none of these
asap plz
plz asap
Answer:
the driving gear must be larger than the driven gear
Explanation:
What was Neptune's distance from the Sun in 1989?
Answer:
4.5 Billion km :)
Explanation:
thats how it is
Answer:
About 3.8 billions miles from the Sun OR 4.82 kilometers
hope this helped!
What happens to sound waves after they are received by our ears?
Answer:
Our ears perceive then sound then it is transmitted to our brain where it is processed into something we can respond to. This all happens in less than a second and we are unaware that we are doing it.
Explanation:
The sound wave bounces off of the ear drum into the inner ear.
Answer:
Sound waves travel from the outer ear and in through the auditory canal, causing the eardrum to vibrate. This in turn causes three small bones in the middle ear to move. The vibrations move through the fluid in the cochlea in the inner ear, stimulating thousands of tiny hair cells.
WHAT IS CHANGE OF STATE
Answer:
a change from one state (solid or liquid or gas) to another without a change in chemical composition
Explanation:
Explanation:
From Solid to. Liquid to Gas A change of state is the change of a substance from one physical form to another. All changes of state are physical changes. The particles have different amounts of energy when the substance is in different states.
A spherical mirror and a thin spherical lens have each a focal length of +10cm , the mirror and the lens are likely to be
Answer: Concave mirror and convex lens
Explanation: A spherical mirror and a thin spherical lens have each a focal length of +10cm, this means that distance of any object from the mirror is +10 metres.
While for the lens, the distance of any object to the other side of the lens is +10 metres. Therefore, the mirror is concave mirror and the lens is a convex lens.
Liquefication occurs when
Answer: Liquefaction occurs when the structure of a loose, saturated sand breaks down due to some rapidly applied loading.
As the structure breaks down, the loosely-packed individual soil particles attempt to move into a denser configuration. Liquefaction most often occurs when three conditions are met:
loose, granular sediment or fill
saturation by groundwater
strong shaking
Answer:
heat is applied
Explanation:with metal and ice
What scientific evidence supports the Big Bang theory?
Universe expansion
Redshift
Composition of the universe
All of the above
None of the above
Answer:A universe expansion
Explanation:
The earliest and most direct observational evidence of the validity of the theory are the expansion of the universe according to Hubble's law (as indicated by the redshifts of galaxies), discovery and measurement of the cosmic microwave background and the relative abundances of light elements produced by BBN.
Which best describes Earth’s magnetic field lines? The field lines go out of Earth near the South Pole, enter Earth in the North Pole, and are aligned with the geographic poles. The field lines go out of Earth near the South Pole, enter Earth in the North Pole, and are not aligned with the geographic poles. The field lines go out of Earth near the North Pole, enter Earth in the South Pole, and are aligned with the geographic poles. The field lines go out of Earth near the North Pole, enter Earth in the South Pole, and are not aligned with the geographic poles.
Answer:
b
Explanation:
did the quiz
Answer:
(B) The field lines go out of Earth near the South Pole, enter Earth in the North Pole, and are not aligned with the geographic poles.
Explanation:
Measurements show that the wavelength of
a sound wave in a certain material is 18.0 cm. The
frequency of the wave is 1900 Hz. What is the speed of
the sound wave?
Answer:a sound wave in a certain material is 18.0 cm. The
frequency of the wave is 1900 Hz. What is the speed of
Explanation:
