What evidence is there that work is being done?
a) A lever is being used.
b) A simple machine makes a task easier.
c) The rock has a larger force than the boy.
d) The boy uses force to move the rock a distance.
Answers
Answer:
The boy uses force to move the rock a distance.
Related Questions
PLEASE HELP. I'LL GIVE BRAINLIEST IF YOU GET IT RIGHT.
Where have we found evidence of the early history of Earth?
a. The Moon, Venus, and Mars
b. Mars, the Moon, and Jupiter
c. Asteroids, the Moon, and Mars
d. The gas planets
Answers
Answer:Most of this ancient space rubble can be found orbiting the Sun between Mars and Jupiter within the main asteroid belt. Asteroids range in size from Vesta – the largest at about 329 miles (530 kilometers) in diameter – to bodies that are less than 33 feet (10 meters) across. The total mass of all the asteroids combined is less than that of Earth's Moon.❤
Mars, the Moon, and Jupiter, Where we have found evidence of the early history of Earth.
What is the evidence of the early history of Earth?The giant-impact theory is currently the one that is most frequently accepted. According to this theory, the Moon was created after the Earth collided with a smaller planet that was around Mars' size.
The Moon was created when the impact's leftover debris gathered in an orbit around Earth. The main asteroid belt, which extends between Mars and Jupiter, is home to the majority of this old space debris.
Asteroids range in size from the largest, Vesta, which has a diameter of roughly 329 miles (530 kilometers), to bodies that are about 33 feet (10 meters) wide. The cumulative mass of all asteroids is less than that of the moon on Earth.
Therefore, option B is correct.
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alcohol thermometer cannot measure the thermometer of boiling water ,why?
Answers
Explanation:
The contents of alcohol are less toxic and will evaporate quickly as compared to the mercury-in-glass thermometer. Since, alcohol starts boiling at 80℃ while the boiling point of mercury is 375℃. ... So, an alcohol thermometer cannot measure the temperature of boiling water as it has the limit to measures up to 80℃.
How does the temp of water change when it is heated on a stove top and it begins to boil.
Answers
Answer:
The temperature will no longer rise with the heat because the energy. When the water is boiled on the steam, the temperature rises when heat is given
Explanation:
Helpppppppp pleaseeeee!!
The mass of an atom is concentrated in its
a. nucleus
b. electron
c. neutron
d. angstrom
e. isotope
Answers
What is the acceleration of an object if it starts at a speed of 3 m/s and increases to
8 m/s in 20 seconds?
Answers
Answer:
0.25 meters per second squared
Explanation:
A green ball is dropped from rest from an elevated position at the same instant that a red ball is launched horizontally (from the same height), which ball will hit the ground first? Assume the balls behave as projectiles.
a. green ball
b. red ball
c. the red and green ball will hit the ground at the same time
d. not enough information given
Answers
Answer:
c. the red and green ball will hit the ground at the same time
Explanation:
if two objects are the same size but one is heavier, the heavier one has greater density than the lighter object. Therefore, when both objects are dropped from the same height and at the same time, the heavier object should hit the ground before the lighter one.
what is the definition for the term Resistance?
Answers
Answer:
Hey mate....
Explanation:
This is ur answer.....
There are 2 definitions :-
The refusal to accept or comply with something.The ability not to be affected by something, especially adversely.Hope it helps!
Brainliest pls!
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Describe when the chemical
reaction occurs in a dry-cell
battery
Answers
Answer:
For a dry-cell battery to operate, oxidation will occur from the zinc anode and reduction will take place in the cathode. The most common type of cathode is a carbon graphite. Once reactants have been turned into products, the dry-cell battery will work to produce electricity.
Explanation:
The battery operates through electrochemical reactions called oxidation and reduction. These reactions involve the exchange of electrons between chemical species. If a chemical species loses one or more electrons, this is called oxidation. The opposite process, the gain of electrons, is called reduction.
write of the following does not represent electrical power in a circuit ?
(a) I²R
(b) IR²
(c)VI
(d) V²/R
Answers
The equations for electrical power are as follows:
P=I^2R
P=VI
P=V^2/R
(You can get this equation by rearranging V=IR, making I the subject to get I=V/R and substituting that into P=VI)
P=E/T
For the equation BaCl2 + Na2SO4 → BaSO4 + 2NaCl, how many chlorine atoms are on the reactants side and on the products side?
Answers
Answer:2 reactants 2 products.
this is a balanced chemical equation. That means the number of chlorine before the arrow will be the same after the arrow
Explanation: i think this answer will help you very much
How long will it take a projectile to hit the ground if it is launched at 4.2 m/s off a 12.6 m high platform?
Answers
Answer: 3
Explanation:
I think you are supposed to divided in those problems? I'm not sure but if you aren't then please let me know. The equation I did was:
12.6 / 4.2 = 3
Hope this helps!! :)
A 50.0 kg crate is pulled 375 N of force applied to a rope. The crate slides without friction.
After being pulled 3.07 meters the crate has a velocity of 5.61 m/s. What is the angle (degrees) made by the rope with the horizontal?
Answers
Hi there!
We can use the work-energy theorem to solve.
Recall that:
[tex]\large\boxed{W = \Delta KE = \frac{1}{2}mv_f^2 - \frac{1}{2}mv_i^2}[/tex]
The initial kinetic energy is 0 J because the crate begins from rest, so we can plug in the given values for mass and final velocity:
[tex]W = \frac{1}{2}(50)(5.61^2) = 786.8025 J[/tex]
Now, we can define work:
[tex]\large\boxed{W = Fdcos\theta}}[/tex]
Now, plug in the values:
[tex]786.8025 = Fdcos\theta\\\\786.8025 = (375)(3.07)cos\theta[/tex]
Solve for theta:
[tex]cos\theta = .6834\\\theta = cos^{-1}(.6834) = \boxed{46.887^o}[/tex]
What is the frequency of a wave with a wavelength of 15 m and a wavespeed of
300 m/s?
Answers
Answer: f=20 (i think)
Explanation:
all I did was divide 300 and 15.
300/15= 20
Help pleaseeeeeeeeeeeeeee
Answers
Answer:
im not the best at this but im gonna try helping you
Explanation:
1. li est deux heures cinquante
2. il est huit heures et demie
3. il est douze heures
4. il est quatre heures cinq
5. il est quatre heures quarante cinq
A 30 g mass is attached to one end of a 10-cm-long spring.
The other end of the spring is connected to a frictionless pivot on
a frictionless, horizontal surface. Spinning the mass around in a
circle at 90 rpm causes the spring to stretch to a length of 12 cm.
What is the value of the spring constant?
Answers
The value of the spring constant of the spring is 14.7 N/m.
The given parameters;
mass attached to the spring, m = 30 glength of the spring, L₀ = 10 cmangular speed of the mass = 90 rpmfinal length of the spring, L₁ = 12 cmThe extension of the spring is calculated as follows;
[tex]\Delta x = L_1 - L_0\\\\\Delta x = 12 \ cm - \ 10 \ cm\\\\\Delta x = 2 \ cm = 0.02 \ m[/tex]
The value of the spring constant of the spring is calculated by applying Hooke's law;
[tex]F = mg = k\Delta x\\\\k = \frac{mg}{\Delta x } \\\\k = \frac{0.03 \times 9.8}{0.02} \\\\k = 14.7 \ N/m[/tex]
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A 1500 kg car travels 50 m north in 20 seconds. What is the magnitude of the average velocity of the car during the 20 second interval?
a. 2.5 m/s
b. 5.0 m/s
c. 6.5 m/s
d. 7.0 m/s
Answers
Answer:
a. 2.5 m/s
Explanation:
50 / 20 = 2.5 m/s
ASAP!!! Imagine you are about to purchase a new refrigerator. There are two models that you are considering. Each
refrigerator is required to have an energy efficiency sticker on the door so that the buyer can be aware of the
cost of running the refrigerator. Refrigerator (A) costs $10.00 a month to operate and $700.00 to buy.
Refrigerator (B) costs $15.00 a month to run and $600.00 to buy. Decide which refrigerator you would purchase,
(A or B) and indicate in the answer box why it would be better for the environment
Answers
Answer:
model A
Explanation:
model A is more expensive to buy but you pay less per month to run it making it a better purchase in the long run. The cheaper cost of running it is better for the environment due to there being less electricity needed to power it.
Energy stores in food would be considered what
Answers
Answer:
Energy stored in food is consider as carbohydrate,protein,fats,etc.
A wave has a wavelength of 1.5 m and a frequency of 6.0 Hz. What is the
speed of the wave?
Answers
Answer:
9 m/sExplanation:
The speed of the wave given only it's frequency and wavelength can be found by using the formula
[tex]c = f \times \lambda[/tex]
where
c is the velocity of the wave in m/s
[tex] \lambda[/tex] is the wavelength in m
f is the frequency in Hz
From the question we have
c = 6 × 1.5 = 9
We have the final answer as
9 m/sHope this helps you
1. Three students are using sports equipment to model the relative motion of
Earth, the moon and the sun.
A. Identify which ball would be used to model the Sun, Earth and the Moo
B. Describe the relative (in relation to each other) motions of these bodies
Answers
Answer:
The golf ball would be revolving around the baseball while the baseball would be revolving around the basketball.
Explanation:
The basketball would be represented as the Sun, the baseball would be represented as the Earth and the golf ball would be represented as the moon. Since the Moon revolves around the Earth and the Earth revolving around the Sun makes a perfect explaination for this question.
1 If you measured the distance travelled by a snail in
inches and the time it took in minutes, what would
be the units of its speed?
Answers
what are the ending materials produced from cell respiration
Answers
Answer:
The products of cellular respiration are carbon dioxide and water
Explanation:
which distance indicator can be used to measure the most distant objects?
Answers
The distance indicator can be used to measure the most distant objects among all indicators stated above is Type Ia supernovae
In the field of Astronomy, there are different kind of distance indicators that can be used to measure the distance objects.
Few among them are :
Cepheids Type Ia supernovae Parallax Main-sequence fittingCepheid variables can be measured up to 18 million light years.
The expansion rate of the universe can also be measured by trying to measure the apparent brightness of the Type Ia supernovae
Parallax means illusory state of an object when viewed from different points
Main sequence fitting makes use of a H-R diagram of the cluster to determine the distance to a stellar cluster.
The distance indicator can be used to measure the most distant objects among all indicators stated above is Type Ia supernovae
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What amount of heat is required to increase the temperature of 75. 0 grams of gold from 150°C to 250°C? The specific heat of gold is 0. 13 J/g°C. A. 750 joules B. 980 joules C. 1300 joules D. 1500 joules E. 2500 joules.
Answers
975 J of heat energy is needed to increase the temperature from 150°C to 250°C of given mass of gold.
From specific heat formula,
[tex]Q = mc \Delta T[/tex]
Where,
[tex]Q[/tex] - Heat absorbed
[tex]m[/tex] - mass of gold = 75. 0 g
[tex]c[/tex] - specific heat of gold = 0. 13 J/g°C
[tex]\Delta T[/tex]- temperature difference = 150°C - 250°C = 100°C
Put the values in the formula,
[tex]Q = 75\times 0.13 \times 100 }\\\\Q = 975 {\rm \ J}[/tex]
Therefore, 975 J of heat energy is needed to increase the temperature of given mass of gold.
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The heat required to increase the temperature of the gold is 980 J
The correct answer to the question is Option B. 980 J
We'll begin by calculating the change in the temperature of the gold
Initial temperature (T₁) = 150 °C Final temperature (T₂) = 250 °C Change in temperature (ΔT) =?ΔT = T₂ – T₁
ΔT = 250 – 150
ΔT = 100 °C
Finally, we shall determine the heat required.
Mass (M) = 75 gChange in temperature (ΔT) = 100 °C Specific heat capacity (C) = 0.13 J/gºC Heat (Q) =?Q = MCΔT
Q = 75 × 0.13 × 100
Q = 975 J
Q ≈ 980 J
The correct answer to the question is Option B. 980 J
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A bullet of mass M1, is fired towards a block
of mass m2 initially at rest at the edge of a
frictionless table of height h as in the figure.
The initial speed of the bullet is vi. Consider
two cases. a соmрlеtеlу inсlаѕtiс one and an
elastic one where the bullet bounces off the block. What is the flight ratio time?
Answers
The ratio of time of flight for inelastic collision to elastic collision [tex](t_A :t_B)[/tex] is 1:2
The given parameters;
mass of the bullet, = m₁mass of the block, = m₂initial velocity of the bullet, = u₁initial velocity of the block, = u₂ = 0Considering inelastic collision, the final velocity of the system is calculated as;
[tex]m_1u_1 + m_2u_2 = v(m_1 + m_2)\\\\m_1u_1 + 0 = v(m_1 + m_2)\\\\v= \frac{m_1u_1}{m_1 + m_2} \ -- (1)\\\\[/tex]
The time of motion of the system form top of the table is calculated as;
[tex]v = u + gt\\\\v = 0 + gt\\\\v = gt\\\\t= \frac{v}{g} \\\\t_A = \frac{m_1u_1}{g(m_1 + m_2)} \ \ ---(2)[/tex]
Considering elastic collision, the final velocity of the system is calculated as;
[tex]m_1u_1 + m_2 u_2 = m_1v_1 + m_2v_2\\\\m_1u_1 + 0 = m_1v_1 + m_2v_2\\\\m_1 u_1 = m_1v_1 + m_2v_2[/tex]
Apply one-directional velocity
[tex]u_1 + (-v_1) = u_2 + v_2\\\\u_1 -v_1 = 0 + v_2\\\\v_1 = v_2 -u_1[/tex]
Substitute the value of [tex]v_1[/tex] into the above equation;
[tex]m_1u_1 = m_1(v_2 - u_1) + m_2 v_2\\\\m_1u_1 = m_1v_2 -m_1u_1 + m_2v_2\\\\2m_1u_1 = m_1v_2 + m_2v_2\\\\2m_1u_1= v_2(m_1 + m_2)\\\\v_2 = \frac{2m_1u_1}{m_1+ m_2} \ --(3)[/tex]
where;
[tex]v_2[/tex] is the final velocity of the block after collision
Since the bullet bounces off, we assume that only the block fell to the ground from the table.
The time of motion of the block is calculated as follows;
[tex]v_2 = v_0 + gt\\\\v_2 = 0 + gt\\\\t = \frac{v_2}{g} \\\\t_B = \frac{v_2}{g} \\\\ t_B = \frac{2m_1u_1}{g(m_1 + m_2)} \ \ ---(4)[/tex]
The ratio of time of flight for inelastic collision to elastic collision is calculated as follows;
[tex]\frac{t_A}{t_B} = \frac{m_1u_1}{g(m_1 + m_2)} \times \frac{g(m_1 + m_2)}{2m_1u_1} \\\\\frac{t_A}{t_B} = \frac{1}{2} \\\\t_A:t_B = 1: 2[/tex]
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You are handed two mystery materials, and told to find out which materials accepts negative charges more easily. A positively-charged, helium-filled balloon is tied to a tabletop with a string a meter long. What's a simple experiment you could run to find out which material accepts electrons more easily?
Answers
The simple experiment you could run to find out which material accepts electrons more easily is to rub them together and move the two charge misery materials one after the other to the positive - charge helium - filled balloon.
According to the fundamental law of static electricity which state that unlike charges attract each other while like charges repel.
The simple experiment you could run if you are handed two mystery materials, and told to find out which materials accepts negative charges more easily charging by friction.
This can be employed by rubbing the two misery materials together and move them one by one to a positively-charged, helium-filled balloon which is tied to a tabletop with a string of a meter long.
The misery material that accepts electron more easily will be attracted to the positive - charge helium - filled balloon. While the gravitational pull will pull down the other misery material. The attraction will not be effective.
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Determine the percent composition of chromium (III) flouride CrF3
(Show your solution)
Answers
Answer:
Molar mass of CrF3, Chromium(III) Fluoride is 108.9913096 g/mol
51.9961+18.9984032·3
Mass percentage of the elements in the composition
Element Symbol Atomic Mass Number of Atoms Mass Percent
Chromium Cr 51.9961 1 47.707%
Fluorum F 18.9984032 3 52.294%
Notes on using the Molar Mass Calculator
Chemical formulas are case-sensitive.
Enter subscripts as simple numbers.
The converter uses a simple dot instead of using a midpoint typographic dot (·) in formulas for adduct molecules, such as water of hydration.
Example: type CuSO4.5H2O instead of CuSO₄·5H₂O.
Explanation:
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How can you use a simple model to describe a wave and its features?
Answers
Answer:
Explanation:
Use mathematical representations to describe a simple model for waves that includes how the amplitude of a wave is related to the energy in a wave. Patterns can be used to identify cause and effect relationships.
A student lifts a backpack straight up with a force of 53.5 N for a distance of 0.65 m. How much work is done on the backpack?
Happy Christmas Eve!!
Answers
Answer:
W = 34.775J
Explanation:
W = F × d
W = 53.5N × 0.65m
W = 34.775J
W = work = unknown
f = force = 53.5N
d = distance = 0.65m
A strong weightless rope has a mass, m, hanging from the middle of it. The tension force on each rope is 25 N, and the rope droops at an angle of 20.0 degrees. How much mass is hanging from the rope?
Answers
By using Lami's theorem, Mass m = 1.75 kg approximately
Given that a strong weightless rope has a mass, m, hanging from the middle of it. If the tension force on each rope is 25 N, and the rope droops at an angle of 20.0 degrees to the horizontal.
By using Lami's theorem, we can get how much mass is hanging from the rope.
Let the angle between the rope = α = 180 - 40
α = 140 degrees
The angle between one of the rope and mass = β = 20 + 90
β = 110 degrees
The angle between the mass and the other rope = γ = 360 - (140 + 110)
γ = 360 - 250
γ = 110 degrees
W/ sinα = T/ sinβ = T/sinγ
W/ sinα = T/ sinβ
Substitute all the necessary parameters
W/sin140 = 25/sin 110
W / 0.643 = 25 / 0.939
W = 17.1 N
Weight W = mg
17.1 = 9.8m
mass m = 17.1/9.8
Mass m = 1.7455 kg
Mass m = 1.75 kg approximately
Therefore, 1.75 kg mass is hanging from the rope.
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