Answer:
418J
Explanation:
Given parameters:
Mass of water = 20g
Specific heat capacity of water = 4.18J/g°C
Initial temperature = 25°C
Final temperature = 20°C
Unknown:
Amount of heat lost to the surroundings = ?
Solution:
The amount of heat lost to the surrounding is the same as the quantity of heat needed to take down the temperature of the water.
Now, to solve this problem, use the mathematical equation below;
H = m c (T₂ - T₁)
H is the amount of heat
m is the mass
c is the specific heat capacity
T is the temperature
1 and 2 are initial and final states.
Now insert the parameters and solve;
H = 20 x 4.18 x (20 - 25)
H = -418J
The quantity of heat the moved from water to the surrounding is 418J
A small steel roulette ball rolls around the inside of a 30 cm diameter roulette wheel. It is spun at 150 rpm, but is slows to 60 rpm over an interval of 5.0 s. How many revolutions does the ball make during these 5.0 s?
Solution :
Given
Diameter of the roulette ball = 30 cm
The speed ball spun at the beginning = 150 rpm
The speed of the ball during a period of 5 seconds = 60 rpm
Therefore, change of speed in 5 seconds = 150 - 60
= 90 rpm
Therefore,
90 revolutions in 1 minute
or In 1 minute the ball revolves 90 times
i.e. 1 min = 90 rev
60 sec = 90 rev
1 sec = 90/ 60 rec
5 sec = [tex]$\frac{90}{60}\times 5$[/tex]
= 75 rev
Therefore, the ball made 75 revolutions during the 5 seconds.
A car has positive acceleration. What information can you infer from this?
The car is changing direction.
The car is speeding up in the same direction as it is traveling.
The car is slowing down and changing the direction it is traveling.
The car is slowing down.
Answer: B: The car is speeding up in the same direction as it is traveling.
Explanation:
I took the test and got it right
katelyn throws a rock which travels 34 m above her hand before it starts to fall. what is the vertical velocity of the rock when it leaves her hand?
Answer:
25.8 m/s
Explanation:
Initial Velocity (u) =?
Final velocity before it starts to fall ; v = 0
Distance (S) = 34 meters
Using the relation :
v² = u² + 2aS
a = - 9.8 m/s²
0 = u² + 2(-9.8)(34)
0 = u² - 666.4
u² = 666.4
u = √666.4
u = 25.814724
Hence, vertical velocity when the rock leaves her hand is 25.8 m/s
You drop a stone down off a bridge. You are able to count to 4.0 seconds when it finally hits the water. How high is the bridge?
Answer:
The height of the bridge is 78.4 m.
Explanation:
Given;
time of the stone motion off the bridge, t = 4.0 s
acceleration due to gravity, g = 9.8 m/s²
The height of the bridge is given by;
h = ut + ¹/₂gt²
where;
u is the initial velocity of the stone, u = 0
h = ¹/₂gt²
h = ¹/₂(9.8)(4)²
h = 78.4 m
Therefore, the height of the bridge is 78.4 m.
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.
Which of the following represents the Law of Conservation of Mass?
(look at picture)
Answer:
the first one
Explanation:
because each one has a blue in it
Option A represents the Law of Conservation of Mass. Therefore, the correct option is A.
A key idea in chemistry is the law of conservation of mass, sometimes referred to as the law of conservation of mass or the law of conservation of matter. According to this, the total masses of reactants and products involved in a chemical reaction in a closed system are the same.
Since atoms are neither created nor destroyed during a chemical reaction, this law states that matter is conserved throughout the process. The atoms in the reactants rearrange their bonds to form new compounds known as products, but the total amount and types of atoms are left unchanged.
Therefore, the correct option is A.
Learn more about Law of Conservation of Mass, here:
https://brainly.com/question/28711001
#SPJ4
As your roller coaster climbs to the top of the steepest hill on its track, when does the first car
have the greatest potential energy?
How does the brightness of light change when a point source of light is brought twice as far away?
Answer:
If its twice as far the light will be twice as bright.
Explanation:
______ 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.
Read more here:
https://brainly.com/question/16019276
9. Two different forces (5 N to the right and 7 N to left) are acting on a 5 kg bowling ball. What would the acceleration of the bowling ball be?
I will give you brainlist
Answer:
0.4m/s² to the left
Explanation:
To solve this problem, we must know that;
Net force = mass x acceleration
Net force is the resultant force on a body that will act like a single force;
Force to left - force to right = mass x acceleration
7 - 5 = 5 x acceleration
2 = 5 x acceleration
Acceleration = [tex]\frac{2}{5}[/tex] = 0.4m/s² to the left
The components of a 10.8-meters-per-second velocity at an angle of 34.° above the horizontal are
9.0 m/s vertical and 6.0 m/s horizontal
13 m/s vertical and 7.5 m/s horizontal
7.5 m/s vertical and 13 m/s horizontal
6.0 m/s vertical and 9.0 m/s horizontal
Answer:
6.0 m/s vertical and 9.0 m/s horizontal
Explanation:
For the vertical component, we use the formula:
Sin(34°) = y / 10.8Then we solve for y:
0.559 = y / 10.8y = 6.0And for the horizontal component, we use the formula:
Cos(34°) = x / 10.8Then we solve for x:
0.829 = x / 10.8y = 9.0So the answer is " 6.0 m/s vertical and 9.0 m/s horizontal".
What is the first step in making a transgenic organism?
A. Find a gene in one species that would be useful if added to the
DNA of another species.
B. Select two parents that have desirable genetic traits and allow
them to reproduce.
C. Insert all of the DNA from the body cell of one individual into the
egg cell of another.
D. Allow an organism with a desirable genetic trait that is recessive
to reproduce asexually.
Answer: its A I took the test
A man has been guarding a house for one hour . Why is it not considered work in science
Answer: because there is no displacement or movement in the watchman's work. according to science when displacement or movement take place it is said to be work. hope this helps you.
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.
name this from taco bell and get brainlest answer :)
Answer:
What "this"??? Where is it " this"???
1.Compare why does things look different under water vs how light rays appear to bend
Answer:
Objects underwater seem closer to the surface than they actually are because light rays from the object bend away from the normal as they pass from water to air making the objects look closer.
Electromagnetism consists of what two processes?
o A. An electric current produces a magnetic field.
B. A moving magnet produces an electric current.
O C. Electric charges attract each other.
D. Permanent magnets produce a magnetic field.
Answer: it’s A and B
Explanation: everyone else on this post was giving you the wrong answer.
An altering magnetic field will cause an altering electric field, and vice versa. Electromagnetic waves are created from these shifting fields. In contrast to mechanical waves, electromagnetic waves can travel without a medium. Thus option A, B is correct.
What are the characteristics of Electromagnetism?The EM wave's magnetic and electric fields are represented by the vectors E and B, respectively. In the case of electromagnetic waves, E and B are always perpendicular to the direction of propagation and to each other.
An oscillating charge generates an oscillating magnetic field, which in turn generates an oscillating electric field in space. As a result, an electromagnetic wave is created by the oscillating electric and magnetic fields that keep regenerating one another.
Therefore, An electric current produces a magnetic field and A moving magnet produces an electric current.
Learn more about Electromagnetism here:
https://brainly.com/question/23727978
#SPJ5
Arrange the following elements in order of increas
ing radius: bromine, potassium, vanadium (23), zinc
Answer:
Potassium > Vanadium > Zinc > Bromine
Explanation:
The size of an atom can be difficult to estimate. It is measured in terms of the atomic radius.
It is the taken as half of the inter-nuclear distance between covalently bonded atoms of non-metallic elements or half the distance between two nuclei in the solid state of metals.
Across a period atomic radius decreases from left to right. Down a group from top to bottom, atomic radii increases progressively.The elements given all lie in the same period so their atomic radius decreases.
Write an example of your own for one of Newton’s Laws. Be sure to state which law it is an example of. please help me
Answer:
What about Newton's law of gravity.
Explanation:
The one with the apple falling on his head.
which of the following is a correct example of an action reaction pair?
A. You push the ball with your foot and the ball pushes the air.
B. When you jump, you push down on the ground and the ground pushes up on you.
C. A swimmer pushes the water with his legs and pulls the water with his arms.
D. The tires on a car push against the road and the front of the car pishes against the wind.
Answer:
its either d or a
Explanation:
imma say d looks pretty right though
What kinds of natural phenomena does the inverse-square law apply to?
Answer:
It applies to diverse phenomena
Explanation:
not sure if u need one, just ask if you do :D
Answer:
Being strictly geometric in its origin, the inverse square law applies to diverse phenomena. Point sources of gravitational force, electric field, light, sound, and radiation obey the inverse square law.
Explanation:
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
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]
can somebody please help with these
Answer:
Fusion
Fission
Explanation:
The first problem describes a nuclear fusion process. In this process;
small atomic nuclei combines to form a larger one. it is accompanied by a large release of energythis energy provides the needed temperature to set up another light nuclei to fuse.The second problem describes nuclear fission,
a heavy nuclide is bombarded with a neutron. the product formed becomes unstable and subsequently breaks down. This leads to a series of chain reactions until stability is attained.If a pulley system with an ideal mechanical advantage of 2,000,000 is used in lifting a 2,000 lb. car, how far would the car move if the effort moved 2 ft.?
_____ ft.
1 x 10-3
1 x 10-6
1 x 10-9
1 x 10-12
Answer:
C
Explanation:
PLS HELPPP! Why are ions harmful and why are they not harmful?
Answer:
This is because we are surrounded by positive ions from electromagnetic fields generated by computers, cell phones, and other electronic devices which can impair brain function and suppress the immune system causing symptoms such as: anxiety, breathing difficulty, fatigue, headaches, irritability, lack of energy, poor concentration, nausea, and vertigo,
Explanation:
Answer:
Ions can be harmful because ions can produce dangerous indoor ozone and can waste space and electricity. Hours of negative ion exposure can produce symptoms of depression. On the other hand, ions can help improve our immune systems by strengthening our immune cells. Ions can also speed up the production of antibiotics.
did u guys know that 75% of stair accidents happen on stairs
Answer:
Shouldn't it be 100%
Explanation:
Please explain in the comment section.
ASAP is the object of soccer ??????
What 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
During a medieval siege of a castle, the attacking army uses a trebuchet to heavy stones at the castle the trebuchet launches the stones with a velocity of + 48.5 m/s at an angle of 42.0 degrees how long does take the stone to hit the ground? For those settings, what is the maximum How high will the stones go Show all your work
Answer:
Explanation:
The question relates to time of flight of a projectile .
Time of flight = 2 u sinθ / g
u is speed of projectile , θ is angle of projectile
= 2 x 48.5 sin42 / 9.8
= 6.6 seconds .
Maximum height attained
= u² sin²θ / g
= 48.5² sin²42 / 9.8
= 107.47 m .