Is pushing a car across a smooth road positive, negative or zero work?
A child pulls on wagon with force of 20 N if the wagon models a total of 10 M in four seconds what is the average power generated by the child in watts
Answer:
[tex]power = \frac{(force \times distance)}{(time)} \\ power = \frac{(20 \times 10)}{4} \\ power = \frac{200}{4} \\ power = 50 \: watts[/tex]
Number of protons are equal to the number of electrons
Explanation:
the no of proton of an element is found in the inner part of the orbital of an element along with the neutron ,also knowing that this two add up to give mass no an element
where neutron+proton=mass no=nucleon no,where proton= electron, unless it carries charges call ion
A 0.78-kg blob of clay strikes a wall at speed 23 m/s. The clay comes to a stop in 0.26 s. What is the average force that the wall exerts on
the clay?
A-69 N
B- 49 N
C- 36 N
D- 55 N
Answer:
A
Explanation:
A room that is kept at the same temperature year-round feels warm to someone who comes in from outside during the winter and cool to someone who comes in from outside during the summer. Explain how this can be true.
Answer:
its warmer than outside in winter and its colder than outside in summer
Explanation:
The perception of warmth or coolness is relative to the temperature difference between the body and the environment. Even though the temperature inside the room remains constant year-round, the relative temperature difference between the environment outside and the room can cause a subjective sensation of warmth or coolness.
What is temperature?Temperature is a physical quantity that measures the degree of hotness or coldness of a body or a substance. It is a scalar quantity, which means it has only a magnitude and no direction.
The SI unit of temperature is the Kelvin (K), but the temperature is commonly measured in degrees Celsius (°C) or degrees Fahrenheit (°F) as well.
The temperature difference is the numerical value of the difference between the temperatures of two objects or substances. It represents the amount of heat that flows from one object to another due to the temperature gradient between them. The temperature difference is also a scalar quantity, and its unit is usually expressed in degrees Celsius or Kelvin.
The temperature difference is important in many areas of science and engineering, including thermodynamics, heat transfer, and meteorology. It is also used to measure the efficiency of heating and cooling systems, such as air conditioners and refrigerators.
Here in this question,
This phenomenon occurs due to the relative difference in temperature between the environment outside and the temperature inside the room. The feeling of warmth or coolness is a subjective sensation that depends not only on the actual temperature but also on the difference in temperature between the person's body and their surroundings.
During the winter, the temperature outside is generally colder than the temperature inside the room which is kept at a constant temperature. When a person comes into the room from the cold outside, their body temperature is lower than the room temperature, so they feel warmer inside the room. This is because the heat from the warm room transfers to the person's body, raising their body temperature and making them feel warmer.
On the other hand, during the summer, the temperature outside is usually warmer than the temperature inside the room. When a person comes into the room from the hot outside, their body temperature is higher than the room temperature, so they feel cooler inside the room. This is because the heat from the person's body transfers to the cooler room, lowering their body temperature and making them feel cooler.
Therefore, the relative temperature difference between the environment outside and the room can cause a subjective sensation of warmth or coolness.
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A sound wave passes from air into water and then into steel. With each change in medium, what happens to the speed of the
wave?
А
It increases
B
It decreases. C
It increases then decreases
D
It decreases then increases
Answer:
A
Explanation:
if its wronge im so sorry
Kennedy and Lilly are in science class. They are asked to prove that some forces are non-contact
forces. The girls list five examples of objects exerting a force on each other without touching. Do you
agree with their list? Tell why or why not?
1. Two like magnetic poles repel each other.
2. Putting on a wool sweater can make your hair get static electricity when it rubs against the
sweater.
3. When you bring two negatively charged balloons near each other they push each other away.
4. Magnets stick to a refrigerator.
Number 1 and 3 demonstrate non-contact forces because the magnets or electrically charged objects exert
forces on each other without touching.
3 is the only example of non-contact forces since like charges repel each other.
Number 1 and 4 are non-contact forces since they both use magnets.
All four are good examples of non-contact forces since they all use either magnets or electric charge which are
non-contact forces.
Answer:1,3 and 5
Explanation:
what force is required to accelerate to 10 kg object to 5.9 m/s/s?
Force required to accelerate 10 kg object to 5.9 m/s/s ?
Mass = 10 kg
Acceleration = 5.9 m/s^2
Force = Mass * Acceleration
Force = 10 kg * 5.9 m/s^2
Force = 59 kg m /s^2 = 59 N
The resistance of a 24 W, 12 V filament lamp depends on the current flowing through the lamp. For currents up to 0.8 A, the resistance has a constant value of 2.5 Ω.
Calculate the potential difference across the lamp when a current of 0.8 A flows through the lamp.
Answer:
V=IR
V=0.8×2.5
V=2V
where V=potential difference
I=Current
R=Resistance
.........
The magnitude of a force is:
A) How fast an object moves when it is pushed
B) How far an object moves when it is pushed
C) how hard an object is pushed or pulled
D) how long it takes to push or pull an object
Answer:
c
Explanation:
force is how hard it is pulled or pushed
what force on a 936kg elevator that is falling freely at 9.8 m/s^2
Answer:
9172.8 N
Explanation:
F = ma
F = (936 kg)(9.8 m/s^2)
F = 9172.8 N
An object's WEIGHT describes how much force the object presses down on the Earth. It can be calculated using the formula WEIGHT = MASS x GRAVITY. REmember that gravity on the Earth is 10m/s2. If Susan has a mass of 70Kg, what is her weight in newtons?
Answer:
700N
Explanation:
W=m×g
W=70kg×10N/m
W=700N
In the universe there are more small stars than large stars. Do you think there are more white dwarfs or black holes? Explain your answer.
Answer: black holes
Explanation:
Tarzan is swinging back and forth
on a 6.25 m long vine. What is the
period of his oscillation?
(Unit = s)
Answer:
5.02s
Explanation:
I got it right in acellus :)
The period of the oscillation when Tarzan is swinging back and forth so it should be 5.01 seconds.
Calculation of the period:Since
Length L = 6.25 m
g = 9.8 m/s²
So,
T = 2π√(L/g)
T = 2π√(6.25 / 9.8)
T = 5.01 sec
Hence, The period of the oscillation when Tarzan is swinging back and forth so it should be 5.01 seconds.
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A circle graph shows that one-fourth of the students in a particular school ride the bus every day. What is this equivalent measurement in radians? In degrees?
Answer:
it's 1.57... radians and 90°
As par circle graph, π/2 radian part of total number of the students in a particular school ride the bus every day.
What is circle graph?Pie charts are another name for circle graphs. The graph is shaped like a circle, with many wedges that each represent a portion of the overall.
The circle graph is commonly referred to as a pie chart since these wedges frequently resemble pie slices. The circle graph's angles are proportionate to the quantity they each represent.
According to circle graph:
Total number of student in the particular school = 2π radian.
So, one-fourth of total number of student in the particular school = 2π/4 radian
= π/2 radian.
Hence, according to circle graph, π/2 radian part of total number of the students in a particular school ride the bus every day.
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3-the-lamps are connected in series. The first-lamp-has-a-current-of2-A and
a resistance of 4 Ohms. The second-lamp has a voltage of 10V. The third-lamp has a
voltage of 6V. Find in this diagram the total voltage, the current for all the lamps, the
total-resistance.
What is the speed of light in a medium if the index of refraction is 1.57?
Answer:
1.91 × 10⁸ m/s
Explanation:
[tex]n = \frac{c}{v} \\ 1.57 = \frac{3.0 \times {10}^{8} }{v} \\ v = 1.91 \times {10}^{8} \: ms {}^{ - 1} [/tex]
The speed of light in a medium if the index of refraction is 1.57 is 1.91 * 10⁸ m/s
The refractive index of a material is the ratio of speed of light in air to speed of light in the medium. It is given by:
Refractive index(n) = speed of light in air(c) / speed of light in material(v)
Given that n = 1.57, c = 3 * 10⁸ m/s, hence:
n = c/v
1.57 = 3 * 10⁸ / v
v = 1.91 * 10⁸ m/s
The speed of light in a medium if the index of refraction is 1.57 is 1.91 * 10⁸ m/s
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A steel fork and a plastic spoon are both at the same temperature. The fork feels colder when you touch it. This is because:
1. Steel conducts thermal energy better than plastic.
2. Plastic loses more thermal energy than steel.
3. Steel contains more thermal energy than plastic.
4. The fork has more mass than the spoon.
Answer: The fork feels colder when you touch it because Steel conducts thermal energy better than plastic. The correct statement is 1
Explanation:
The ability of a material to transfer heat energy in an environment is known as thermal conductivity. It feels cooler to touch a steel spoon than a plastic spoon found in the same temperature because steel which is a type of metal is a highly efficient thermal conductor than spoon which is a plastic.
Metals can be defined as those substances which forms positive ion in a chemical reaction by lossing it's electrons. It has the following properties:
--> it is solid at room temperature
--> it has high melting point
--> it has high boiling point and
--> it is malleable.
Metals are said to be good thermal conductor because they contain free flowing conduction electrons. Therefore, when you touch a steel spoon and plastic spoon, it feels cooler because the steel metal is able to conduct heat away from your hand faster than the plastic which is a poor conductor of heat.
Answer:
1. Steel conducts thermal energy better than plastic.
Explanation:
Both objects are at the same temperature, and when you touch them, you feel the steel to be colder.
This happens because steel is a better thermal conductor, then when you touch it, it "steals" more thermal energy from you than the plastic.
As the amount of thermal energy transmitted is greater for the steel, you will feel it to be colder.
Then the correct option is the first one, steel conducts thermal energy better than plastic.
PLS HELP (50 POINTS) I WILL ALSO MARK BRAINLIEST!!!
Some help please :)
At which stage in the life cycle of a star is helium combined to form elements lithium through iron? Explain.
Answer:
Explanation:
During the formation of the universe some 14 billion years ago in the so-called ‘Big Bang’, only the lightest elements were formed – hydrogen and helium along with trace amounts of lithium and beryllium. As the cloud of cosmic dust and gases from the Big Bang cooled, stars formed, and these then grouped together to form galaxies.
Julio decides to break the Guinness Book of World Records for bungee jumping. He goes
to the Macau Tower in China where the current record is held. After several heart-pounding
seconds, he leaps from a height of 233 meters. If his weight is 86 kilograms, what would his
potential energy be just prior to jumping? If when he jumped he reached a speed of 15 m/s, what
is his kinetic energy? Explain your answer
Answer:
a) U = 1.96 10⁵ J, b) K = 9.675 10³ J
Explanation:
a) the potential energy is
U = m g h
where zero energy in general takes the floor
let's calculate
U = 86 9.8 233
U = 1.96 10⁵ J
b) They ask for kinetic energy and give us the speed of man
K = ½ m v²
let's calculate
K = ½ 86 15²
K = 9.675 10³ J
what is the demand for resources, such as food, water, and shelter.
What type of friction is it when two students are pushing a box that is at rest
Electromagnetic Spectrum Lab Report
if you've done this assignment or know what im talking about please helps me! if you get it correct i will give you brainliest!!!!!!!!!!!!!
Objectives(s):
In your own words, what is the purpose of this lab?
Hypothesis:
In this section, please include the predictions you developed during your lab activity. These statements reflect your predicted outcomes for the experiment.
Procedure:
The materials and procedures are listed in your virtual lab. You do not need to repeat them here. However, you should note if you experienced any errors or other factors that might affect your outcome. Using your summary questions at the end of your virtual lab activity, please clearly define the dependent and independent variables of the experiment.
The dependent variable is the one that changes as a result of the independent variable. The spectrum emitted by the unknown celestial object in this situation.
What is the electromagnetic spectrum?The electromagnetic spectrum refers to the variety of frequencies (the spectrum) of electromagnetic radiation, as well as the wavelengths and photon energies associated with each frequency.
The goal of the electromagnetic spectrum experiment is to determine what elements are present in the atmospheres of the planets and moons by examining their absorption spectrums.
The electromagnetic spectrum encompasses electromagnetic waves with frequencies ranging from below one hertz to above 1025 hertz,
The frequency corresponds to wavelengths ranging from thousands of kilometers to a fraction of an atomic nucleus's size.
The electromagnetic waves within each frequency band are given various names, starting at the low frequency (long wavelength) end of the spectrum.
Hence the dependent variable is the one that changes as a result of the independent variable.
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Answer:
Explanation: Electromagnetic Spectrum Lab Reportif you've done this assignment or know what im talking about please helps me! if you get it correct i will give you brainliest!!!!!!!!!!!!!Objectives(s):In your own words, what is the purpose of this lab?Hypothesis:In this section, please include the predictions you developed during your lab activity. These statements reflect your predicted outcomes for the experiment.
If a 1.8 m tall man that weighs 90 kg stands next to a 10 kg box resting on the ground, the total work done if he lifts the box to the top of his head will be 2,940 J.
True or False
Answer:
false
Explanation:
An example of a waste product of cellular respiration is
a]feces
b]oxygen
c]carbon dioxide
d]ammonia
Answer:
(C) Carbon Dioxide!
Explanation:
This is what animals, and even plants, breath out. :)
how does the sun rise and set
a.earth orbit around the sun
b.The sun is center of solar system
c.earth rotates on it tilted axis and orbit around the sun at the same time
Answer:
c. earth rotates on it tilted axis and orbit around the sun at the same time
Explanation:
Earth rotation can be defined as the amount of time taken by planet earth to complete its spinning movement on its axis.
This ultimately implies that, the rotation of earth refers to the time taken by earth to rotate once on its axis. One spinning movement of the earth on its axis takes approximately 24 hours to complete with respect to the sun. Thus, this makes us to experience day and night (sun rise and sun set) due to the rotation of planet about its axis.
Hence, the sun rise and set because the earth rotates on it tilted axis and orbit around the sun at the same time
The Law of Octaves is a relationship that can be observed when
elements are ordered by atomic mass. Newlands observed that every
____ element exhibited similar properties.
Answer:
8 elements
Explanation:
It’s right ✌
When you blow across the top of a
soda bottle, it acts like a closed
pipe. If the inside of the bottle is
0.150 m long, what is the
fundamental frequency you hear?
(Speed of sound = 343 m/s)
(Unit = Hz)
Answer:
572
Explanation:
Got it right on Acellus, you take the velocity and divide it by 4 times the length.
PLS HURRY THIS IS DUE IN 5 mins
(a) Waves P and Q have the same
but wave P has twice the
of wave Q.
(b) Waves Q and R have the same
but wave R has twice the
of wave Q.
(c) Wave
shows a steady frequency but changing amplitude.
(d) Wave
shows steady amplitude but a changing frequency
Tel Waves
and
have a lowamplitude and a steadvafrecuency
Answer:
(a) Waves P and Q have the same wavelength but wave P has twice the amplitude of wave Q.
(b) Waves Q and R have the same amplitude but wave R has twice the wavelength of wave Q.
(c) Wave T shows a steady frequency but changing amplitude.
(d) Wave S shows steady amplitude but a changing frequency.
e) Waves Q and R have a low amplitude and a steady frequency.