why is a pencil bent when bent in water
Answer:
Refraction
Explanation:
A pencil bends when it enters the water media due to the phenomenon of refraction.
Refraction is one of the properties of waves. Refraction of light occurs which it crosses from a region having different density values. Water is denser than air. As light moves from air to wave it becomes refractedWhat are earth's three main layers? *
O Core, mantle, and surface
O Core, mantle, and crust
O Inner core, outer core, and mantle
O Upper mantle, lower mantle, and crust
Answer:
inner core ,outer core,and mantle
If a truck and a bug are both moving, which takes more force to stop?
During take-off a 5kg model rocket, initially at rest, burns fuel for 4.6s causing its speed to increase from rest to 39m/s during this time despite experiencing a 60N drag.
Answer:
The height is "89.61 m". A further explanation is given below.
Explanation:
According to the question,
Mass of rocket,
m = 5 kg
Time,
t = 4.6 s
Initial speed of rod
u = o m/s
Final speed,
v = 39 m/s
drag,
= 60 N
So,
⇒ acceleration, [tex]a=\frac{v-u}{t}[/tex]
[tex]=\frac{39-0}{4.6}[/tex]
[tex]= 8.478 \ m/s^2[/tex]
⇒ [tex]F_{net}= Net \ force[/tex]
[tex]=ma[/tex]
[tex]=5\times 8.478[/tex]
[tex]=42.89 \ N[/tex]
Now,
The thrust will be:
⇒ [tex]Thrust-weight-drag=Net \ force[/tex]
⇒ [tex]Thrust-(5\times 9.8)-60=42.89[/tex]
⇒ [tex]Thrust-49-60=42.89[/tex]
⇒ [tex]Thrust-109=42.89[/tex]
⇒ [tex]Thrust=42.89+109[/tex]
⇒ [tex]Thrust=151.89 \ N[/tex]
The height will be:
⇒ [tex]h=\frac{1}{2} at^2[/tex]
[tex]=\frac{1}{2}\times 8.47\times (4.6)^2[/tex]
[tex]=\frac{1}{2}\times 8.47\times 21.16[/tex]
[tex]=89.61 \ m[/tex]
how much force is needed to accelerate a 20 kg mass at a rate of 4 m/s to the second power?
Answer:
So 55 Newtons are needed.
Answer:
80 N
Explanation:
mass (m) = 20kg
acceleration (a) = 4m/s^2
Force (F) = ?
.°. F = ma
= 20 × 4 = 80
.°. F = 80 N
Thus, The Force is needed to accelerate a 20 kg mass at a rate of 4 m/s^2 is 80 N
-TheUnknownScientist
What is the maximum speed when the conditions are mass =450 kg, initial height= 30 m, and the roller coaster is initially at rest?
A. 30 m/s
B. 24.2 m/s
C. 93.9 m/s
D. 132, 300 m/s
Answer:
B. 24.2 m/s
Explanation:
Given;
mass of the roller coaster, m = 450 kg
height of the roller coaster, h = 30 m
The maximum potential energy of the roller coaster due to its height is given by;
[tex]P.E_{max} = mgh\\\\PE_{max} = 450 *9.8*30\\\\PE_{max} = 132,300 \ J[/tex]
[tex]P.E_{max} = K.E_{max} \ (law \ of \ conservation\ of \ energy)[/tex]
[tex]K.E_{max} = \frac{1}{2}mv_{max}^2\\\\ v_{max}^2 = \frac{2K.E_{max}}{m}\\\\ v_{max}^2 = \frac{2*132300}{450}\\\\ v_{max}^2 =588\\\\v_{max} = \sqrt{588}\\\\ v_{max} = 24.2 \ m/s[/tex]
Therefore, the maximum speed of the roller coaster is 24.2 m/s.
Answer:
1. 24.2 m/s
2. 20.4 m
3. 22.5 m/s
4. 109,375 J
5. It is easy to calculate new scenarios.
Explanation:
5/5 on the Maximum Energy Quick Check
Choose the pair of elements that will most likely have the greatest ionic character.
a. K and N
b. K and S
c. N and Br
d. S and Br
Answer:
K and N
Explanation:
Ionic character depends on the electronegativity difference between the bonding elements. The greatest the elctronegativity diffference the greatest the ionic character. The electronegativity difference between K and N is the greatest among the four options as N is one of the most electronegative elements.
how are theories and laws connected
Answer:
Laws are statements about something that's been observed and stated while a theory is an explanation of what's been observed. This connection between them forms a main idea that many people regulate as "what's normal."
Explanation:
Answer:
A hypothesis is a limited explanation of a phenomenon; a scientific theory is an in-depth explanation of the observed phenomenon. A law is a statement about an observed phenomenon or a unifying concept, according to Kennesaw State University. ... However, Newton's law doesn't explain what gravity is, or how it works.
for e.g:
The particle theory and Darwin's theory of human origin.
Which of the following is a source of thermal energy that is absorbed by Earth's atmosphere?
Answer:
100% of the energy entering earth's atmosphere comes from the sun. ~50% of the incoming energy is absorbed by the earth's surface i.e. the land and oceans.
Momentum,
A ball hits a wall and reverses course. According to
Newton's Third Law, which of these must be true? Select all
that apply.
Choose all that apply
The wall exerts a force on the ball.
The wall moves toward the ball.
The wall moves away from the ball.
The ball moves away from the wall.
The ball exerts force on the wall.
The ball moves towards the wall.
Answer:
THE WALL MOVES AWAY FROM THE BALL
Explanation:
NEWTON'S THIRD LAW STATES THAT THERE IS A OPPOSITE REACTION
Calculate the momentum of the following objects:
a. 75kg speed skater moving forward at 16m/s
b. 135kg ostrich running north at 16.2m/s
c. 0.8 kg kitten running to the left at 6.5 m/s
Answer:
momentum(M in Kgm/s)=mass(m in Kg) *velocity(v in m/s)
a) M=m*v. m=75kg,v=16 m/s
M =75*16
M=1200Kgm/s
b)M=135*16.2
M=2187Kgm/s
c)M = 0.8*6.5
M=5.2Kgm/s
Hope it is helpful?
The momentum of an object having mass
a) 75kg speed skater moving forward at 16m/s is 1200 kg.m/s
b) 135kg ostrich running north at 16.2m/s is 2187 kg.m/s
c) 0.8 kg kitten running to the left at 6.5 m/s is 5.2 kg.m/s
What is momentum ?Momentum is defined as mass times velocity of body. it is denoted by p and its SI unit is Kg.m/s. It has both magnitude and direction. it is a vector quantity.
i.e. p = mv
a) Given,
mass m = 75Kg
velocity v = 16m/s
momentum p = 75× 16 = 1200 kg.m/s
b) Given,
mass m = 135Kg
velocity v = 16.2m/s
momentum p = 135×16.2 = 2187 kg.m/s
c) Given,
mass m = 0.8Kg
velocity v = 6.5m/s
momentum p = 0.8×6.5 =5.2 kg.m/s
Hence momentums of a), b) and c) are 1200 , 2187 and 5.2 kg.m/s respectively.
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Question 7 of 10 A strong magnet is used to separate certain items from other recyclables Which two items found in recyclables would be attracted to the magnet? O A. Cardboard boxes o B. Iron cooking pans O c. Glass mixing bowls O D. Flexible refrigerator magnets
Answer:
D. Flexible refrigerator magnets
B. Iron cooking pans
The strong magnet can attract other magnetic materials from the mixture. They are iron cooking pans and flexible refrigerator magnets. Hence, options B and D are correct.
What are magnetic materials ?Magnetic materials are those having a permanent magnetic dipoles and produces strong magnetic field. Permanent magnets are ferromagnetic in nature. Their magnetic dipoles align along with the applied magnetic field.
A magnetic material can attract other magnet through their opposite poles in contact. Therefore, magnetic materials such as iron, nickel, etc.can be attracted by a bar magnet.
Here, the flexible refrigerator magnets and the iron cooking pans would be attracted to the strong magnet and they can be separated from the other recyclable materials.
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Alice added sodium chloride to water and stirred the water for several minutes. Alice is most likely trying to demonstrate that ionic compounds are hard. can dissolve. are clear. can melt.
sorry im late can dissolve is the answer <3
Answer:
dissolve
Explanation:
A skateboarder starting from rest accelerates down a ramp at 2 m/s for 2 s. What is the final speed of the skateboarder?
Answer: 4m/s
Explanation:
Speed = distance/time.
= 2/2 = 1 m/s
What is speed ?"Speed is defined as the distance travelled by a body per unit time." Its SI unit is m/s.
The distance covered by an object in unit time. In other words, the rate at which the object is moving is called speed
What is distance ?"Distance is the actual path length traveled by an object in the given interval of time during the motion. It is a positive scalar quantity."
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Q #3: You are on the International Space Station (in space) and working on the outside of the Space Station. Your rope holding you to the Space Station snaps and you start to float away. What will happen to you according to Newton's First Law? *
A. You will continue to float away until you suddenly come to a stop.
B. You will continue to float away until you slow down eventually.
C. You will continue to float away at the same speed and in the same direction forever unless an unbalanced force acts on you.
What are some examples of EM waves
Answer:
MicrowavesHeatwaves Ultraviolent waves WiFi signal4G/5G signalsExplanation:
All of these are examples of electromagnetic radiation or energy.
The spectra comprises most energy and matter we can account for so far.
The main distinction between EM waves and for example longitudinal acoustic waves is the medium of energy transfer (and rules). EMWs are subject to the idiosyncratic effects of Quantum Mechanics while other 'macro' waves whose medium relies on gross material, are apparently not.
which activity performed by a medical professional is primarily based on understanding of physics?
Answer:
Thank you and please rate me as brainliest as it will help me to level up
______ are NOT a source of arsenic in the environment. *
Pesticides
Rocks that naturally contain the element
Weed killers
Old water pipes
What policy change was based on the results of the students’ water-testing project? *
The U.S. Environmental Protection Agency established a national limit for arsenic in drinking water.
The national limit for arsenic in drinking water was lowered to 5 parts per billion (ppb).
The national limit for arsenic in drinking water was increased to 10 ppb.
New Hampshire’s limit for arsenic in drinking water was lowered from 10 ppb to 5 ppb.
Damage to the body’s _______ system can affect brain development, learning, and memory. *
cardiovascular
muscular
endocrine
nervous
4. The element arsenic is a ______. *
metalloid
metal
nonmetal
noble gas
5. Explain how the characteristics of arsenic can make it difficult to know whether a well is contaminated. *
Answer:
A
C
D
A
Explanation:
______ are NOT a source of arsenic in the environment.
A. PesticidesThe policy change which was based on the results of the students’ water-testing project is:
C. The national limit for arsenic in drinking water was increased to 10 ppb.Damage to the body’s _______ system can affect brain development, learning, and memory. *
D. NervousThe element arsenic is a ______. *
A.MetalloidPesticides are those chemicals which are used particularly in killing pests such as harmful insects which cause a nuisance to the environment.
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For part 3 of 3, just enter magnitude (positve number)
A 1933 kg car has a speed of 14 m/s when it hits a tree. The tree doesn’t move and the car comes to rest.
Find the change in kinetic energy of the car. Answer in units of J.
Find the amount of work done by the car as its front is pushed in.
Answer in units of J.
Find the magnitude of the force that pushed the front of the car in by 38 cm.
Answer in units of N.
Answer:
The change in kinetic energy of the car is -189434 joules.
The work done by the car is 189434 joules.
The magnitude of the force that pushed the front of the car is 498510.526 newtons.
Explanation:
Given that the car is moving on a horizontal ground, by the Principle of Energy Conservation and the Work-Energy Theorem we get the following identity:
[tex]\Delta K+\Delta W = 0[/tex] (1)
Where:
[tex]\Delta K[/tex] - Change in the translational kinetic energy of the car, measured in joules.
[tex]\Delta W[/tex] - Work done by the car, measured in joules.
By applying the defintions of translational kinetic energy and work, we expand and simplify the resulting equation:
[tex]\frac{1}{2}\cdot m \cdot (v_{f}^{2}-v_{o}^{2})+F\cdot \Delta s = 0[/tex] (2)
Where:
[tex]m[/tex] - Mass, measured in kilograms.
[tex]v_{o}[/tex], [tex]v_{f}[/tex] - Initial and final speeds of the car, measured in meters per second.
[tex]F[/tex] - Force exerted by the car, measured in newtons.
[tex]\Delta s[/tex] - Travelled distance of the front of the car, measured in meters.
The change in the kinetic energy of the car and the work done by the car are, respectively: [tex](v_{o} = 14\,\frac{m}{s}, v_{f}= 0\,\frac{m}{s}, m = 1933\,kg, \Delta s = 0.38\,m)[/tex]
Translational kinetic energy
[tex]\Delta K = \frac{1}{2}\cdot m\cdot (v_{f}^{2}-v_{o}^{2})[/tex]
[tex]\Delta K = \frac{1}{2}\cdot (1933\,kg)\cdot \left[\left(0\,\frac{m}{s} \right)^{2}-\left(14\,\frac{m}{s} \right)^{2}\right][/tex]
[tex]\Delta K = -189434\,J[/tex]
Work done by the car
[tex]\Delta W = -\Delta K[/tex]
[tex]\Delta W = 189434\,J[/tex]
Magnitude of the force
[tex]F = \frac{\Delta W}{\Delta s}[/tex]
[tex]F = \frac{189434\,J}{0.38\,m}[/tex]
[tex]F = 498510.526\,N[/tex]
The change in kinetic energy of the car is -189434 joules.
The work done by the car is 189434 joules.
The magnitude of the force that pushed the front of the car is 498510.526 newtons.
Which part of an object's rate of change best defines acceleration?
A.position
B.speed
C.velocity
D.force
Answer:
Velocity
Explanation: If you are going down hill, (Which is one direction) you will gain more speed by, gravity, friction, and most importantly velocity.
A girl cycles for 3hrs at a speed of 40 km/h. What distance did she travel? Must show your work
Answer:
120 mExplanation:
The distance covered by an object given it's velocity and time taken can be found by using the formula
distance = velocity × time
From the question we have
distance = 40 × 3
We have the final answer as
120 mHope this helps you
5.
Classify the following as examples of newton's first law, second law and third law. Justify your
classification. [3marks]
a. A stone in the ground
b. Two people walking together
C. A hammer pushes a nail
When you set a heavy bag down on the ground, you are doing _______ work on it.
When you set a heavy bag down on the ground, you are doing negative work on it.
A cook had a jar containing a sweet food and a jar containing a sour food. The sweet food has a strong attraction between its molecules, and the sour food has a weak attraction between its molecules. At room temperature, both foods are liquids. The cook left both jars in a place where the same amount of energy was transferred into both substances. When she returned, one of the foods had changed phase while the other had not. Which food changed phase, and how did it change?
Answer:
The sweet food changed because the molecules were able to move fast enough to overcome the attraction between them with its molecules now moving away from each other.
Explanation:
We are told that the sweet food has a strong attraction between its molecules, and the sour food has a weak attraction between its molecules.
This means that the molecules in the sweet food would be moving at a faster rate than in the sour food because of the strong forces of attraction. Therefore, the molecules in the sweet food would be moving far away from each other hence the change of phase.
The sweet food changed since the molecules were capable to move fast i.e. sufficient to overcome the attraction between them with its molecules.
information regarding molecules:
The sweet food should contain the strong attraction between its molecules, and the sour food contains weak attraction between its molecules.This represent that the molecules in the sweet food would be moving at a faster rate as compared to the in the sour food because of the strong forces of attraction.Learn more about the molecure here: https://brainly.com/question/19922822?referrer=searchResults
Twenty (20.0) mL of argon gas (Ar) is stored at STP. If the temperature and pressure are both doubled, what is the new volume?
PLZZ ANSWER ASAP!!
Answer:
The new volume is the same as the initial volume, i.e. 20 mL.
Explanation:
To find the new volume we can use the Ideal gas law:
[tex] PV = nRT [/tex]
Where:
P: is the pressure
V: is the volume
R: is the gas constant
n: is the number of moles
T: is the temperature
Initially, we have:
[tex] \frac{P_{i}V_{i}}{T_{i}} = nR [/tex] (1)
In the final state:
[tex] \frac{P_{f}V_{f}}{T_{f}} = nR [/tex] (2)
By equating equation (1) and (2) we have:
[tex] \frac{P_{i}V_{i}}{T_{i}} = \frac{P_{f}V_{f}}{T_{f}} [/tex]
[tex] \frac{P_{i}V_{i}}{T_{i}} = \frac{2P_{i}V_{f}}{2T_{i}} [/tex]
[tex]V_{f} = \frac{2T_{i}*P_{i}*V_{i}}{T_{i}*2P_{i}}[/tex]
[tex] V_{f} = V_{i} [/tex]
[tex] V_{f} = 20.0 mL [/tex]
Therefore, the new volume is the same as the initial volume, i.e. 20 mL.
I hope it helps you!
A green ball has a mass of 0.525 kg and a blue ball has a mass of 0.482 kg. A croquet player strikes the green ball and it gains an initial velocity of 2.26 m/s. It then strikes the blue ball, which is initially at rest. After the collision, the green ball has a velocity of 1.14 m/s in the same direction. If the balls roll on a frictionless surface and the collision is head-on, what is the final velocity of the blue ball? (Round your answer to the nearest hundredths place.)
Answer:
v' = 1.21 m/s
Explanation:
Mass of a green ball, m = 0.525 kg
Mass of a blue ball, m' = 0.482 kg
Initial velocity of green ball, u = 2.26 m/s
Initial velocity of blue ball, u' = 0 (at rest)
After the collision,
The final velocity of the green ball, v = 1.14 m/s
We need to find the final velocity of the blue ball after the collision if the collision is head on. Let v' is the final velcity of the blue ball. Using the conservation of momentum to find it :
[tex]mu+m'u'=mv+m'v'\\\\0.525 (2.26)+0=0.525 (1.14)+0.482v'\\\\0.588=0.482v'\\\\v'=\dfrac{0.588}{0.482}\\\\v'=1.21\ m/s[/tex]
So, the final velocity of the blue ball is 1.21 m/s.
The law of conservation of momentum states that momentum is conserved. This means that if the initial momentum of a system is 50 kg m/s, and
none of the kinetic energy is transformed to any other form, then the final momentum will be
kg m/s.
Answer:
50kgm/s
Explanation:
From the law of conservation of momentum, a system that starts with an initial momentum of 50kgm/s will end up with a momentum of 50kgm/s in its final state.
The law of conservation of momentum states that "in an isolated system, momentum is neither created nor destroyed but transformed from one form to another". From this law, the starting and ending momentum must be the same.A manufacturer selected a metal to use in producing a lightweight button for clothing. A metal that has a density of 2.71 g/cm3 was selected.
metal, data, metal, mass, grams, volume, centimenters, cubed, 1, 22.1, 3.00, 2, 42.0, 4.00, 3, 9.32, 5.00, 4, 8.13, 3.00,
Which of the metals was selected?
Metal 1
Metal 2
Metal 3
Metal 4
Just find the density of every metal and select the one with a density of 2.71 g/cm³ . This is:
Metal 1
ρ = m/V
ρ = 22.1 g / 3 cm³
ρ = 7.367 g / cm³
Metal 2
ρ = m/V
ρ = 42 g / 4 cm³
ρ = 10.5 g / cm³
Metal 3
ρ = m/V
ρ = 9.32 g / 5 cm³
ρ = 1.864 g / cm³
Metal 4
ρ = m/V
ρ = 8.13 g / 3 cm³
ρ = 2.71 g / cm³
R / Metal 4 was selected.
hi everyone........
Answer:
hiiiiiiiiiiiiiiiiiiiiiiiiii
Answer:
Hiii , how are you holding up with corona?
Explanation:
A scientist is testing a fertilizer used to make corn grow taller. The scientist
adds different amounts of fertilizer to each field. He then measures the height
of the corn in each field. What is the manipulated variable in this experiment?
A. The height of the corn
B. The amount of fertilizer
C. The number of experiment groups
D. The number of pieces of corn
the height of the corn maybe