Answer:
C. Exothermic Reaction
Explanation:
Let's go through the choices
A. Combustion - Combustion is a highly exothermic / redox reaction which produces light and heat (i.e basically it bursts into flames). In the description, the only reaction is that it feels warm, hence this is not the answer.
B. Endothermic - Recall that endothermic reactions absorbs heat and thus cools the surroundings thereby making test tube feel cooler. this is obviously not the case so this is not the answer.
C. Exothermic - Recall that exothermic reactions releases heat and thus causes the surroundings thereby making the test tube feel warmer (or hotter in some cases). This describes our situation so THIS IS THE ANSWER.
D. Endergonic reactions require an input of energy from an external source that is adsorbed by the reaction (for example if heat was applied by an external source). In this case, there is no mention of additional energy sources. Hence this is probably not the answer.
Need help on circuit question
You have a large flashlight that takes 4 D-cell batteries, each with a voltage of 1.5 volts. If the current in the flashlight is 2.0 amps, what is the
resistance?
A 12 ohms
B 0.75 ohms
C 3.0 ohms
D.0.5 ohms
E. 6.0 ohms
Answer:
The answer is "C. 3.0 ohms".
Explanation:
Ohm's law states the following:,
V = IR
where:
Voltage (V) = 1.5 volts × 4 batteries = 6.0 volts
Current (I) = 2.0 amps
Resistance (R) = ? ohms
To solve for Resistance (R) the equation must be rearranged this way:
R = V / I
Then, the variables must be replaced with the known values:
R = 6.0 volts / 2.0 amp
R = 3.0 ohms
The answer is C. 3.0 ohms.
------------
P.D: I got it right on PLATO
Which statement is NOT an advantage of renewable resources? A They produce clean energy. B They are expensive to collect and transform into energy. C They are safe for the environment. D They replenish quickly.
Answer:
B. They are expensive to collect and transform into energy.
Explanation:
All of the other options are positive aspects of renewable resources. B is the only disadvantage of renewable resources given in the question.
Answer:
They are expensive to collect and transform into energy.
Explanation:
Edge
30
. Which of the following represents the
statement "The difference of two square
numbers is positive
Answer:
In mathematics, the difference of two squares is a squared (multiplied by itself) number subtracted from another squared number. Every difference of squares may be factored according to the identity. in elementary algebra.
Explanation:
A chocolate wrapper is 6.7 cm long and 5.4 cm wide. Calculate its area up to
reasonable number of significant figures.
Object A has a mass of 10 kg and is moving at a velocity of 2.0
m/s. So Object A's momentum is - kg. m/s.
Answer:20kgm/s
Explanation:
Mass=10kg
Velocity=2m/s
Momentum=mass x velocity
Momentum=10 x 2
Momentum=20
Momentum=20kgm/s
The object with mass m when moving with the velocity, its momentum can be calculated. The momentum of the object A is 20 kg.m/s.
What is momentum?Momentum is the product of mass and velocity of a moving object.
If the momentum is p, the mass of the object is 10 kg and the velocity is 2.0 m/s, then the momentum will be
p = 10 × 2.0
p = 20 kg.m/s
Thus, the momentum of the object A is 20 kg.m/s
Learn more about momentum.
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Rohit placed a pencil perpendicular to principal axis in front of a converging
mirror of focal length 30 cm. The image formed is twice the size of the pencil.
Calculate the distance of the object from the mirror.
Answer:
45 cm ( in my opinion)♀️
Explanation:
( Using the mirror formula)
1/ u + 1/v = 1/f
( introducing magnification; m into the formula )
u( 1/u + 1/v ) =u×1/f
1 + u/v =u/f
( But u/v =1 ÷v/u= 1/m)
1 +1/m =u/f
(Supposing m is actually equal to 2, and f =30 cm, then;)1 + 1/2 =u/30
2+1= u/15
3=u/15
3×15=u
45 cm=u
What energy transformations take place in Joule's system?
Which of the following statements about developing a personal fitness program is NOT true?
A When developing a personal fitness program, it is important to implement strategies that will help
maintain the program as well as give it a successful start
B. Personal factors such as age, health concerns, and likes are important to consider when developing
a personal fitness program
C. The starting skill level of the physical activities included in a personal fitness program should be
determined from other individuals' fitness programs
D. The FITT principle should be used when developing a personal fitness program,
Please select the best answer from the choices provided
A
B
Save and Exit
Next
Answer:
C
Explanation:
The starting skill level of the physical activities included in a personal fitness program should be determined from other individuals' fitness programs is a statement which is not true. Everyone starts their personal fitness journey at a different level which should be regarded . A fitness test should be taken to determine where an individual should start their new lifestyle.
Answer:
C. I got it right :)
Explanation:
An air-track glider attached to a spring oscillates between the 10.0 cm mark and the 61.0 cm mark on the track. The glider completes 11.0 oscillations in 31.0 s
Answer:
T = 2.82 seconds.
The frequency [tex]\mathbf{f = 0.36 \ Hz}[/tex]
Amplitude A = 25.5 cm
The maximum speed of the glider is [tex]\mathbf{v = 56.87 \ rad/s}[/tex]
Explanation:
Given that:
the time taken for 11 oscillations is 31 seconds ;
SO, the time taken for one oscillation is :
[tex]T = \frac{31}{11}[/tex]
T = 2.82 seconds.
The formula for calculating frequency can be expressed as :
[tex]f = \frac{1}{T}[/tex]
[tex]f = \frac{1}{2.82}[/tex]
[tex]\mathbf{f = 0.36 \ Hz}[/tex]
The amplitude is determined by using the formula:
[tex]A = \frac{d}{2}[/tex]
The limits that the spring makes the oscillations are from 10 cm to 61 cm.
The distance of the glider is, d = (61 - 10 )cm = 51 cm
Replacing 51 for d in the above equation
[tex]A = \frac{51}{2}[/tex]
A = 25.5 cm
The maximum speed of the glider is:
[tex]v = A \omega[/tex]
where ;
[tex]\omega = \frac{2 \pi}{T}[/tex]
[tex]\omega = \frac{2 \pi}{2.82}[/tex]
[tex]\omega = 2.23 \ rad/s[/tex]
[tex]v = A \omega[/tex]
[tex]v = 25.5 *2.23[/tex]
[tex]\mathbf{v = 56.87 \ rad/s}[/tex]
Determine the magnetic flux through a square loop of side a if one side is parallel to, and a distance b from a straight wire that carries a current I.
1. If the loop is pulled away from the wire at speed v, what emf is induced in it?
2. Which way does the induced current flow through the loop?
3. How does the emf vary in time, if the initial position of the left vertical side was b0 at time t=0?
4. Determine the force F required to pull the loop away from the line of current.
Answer:
Find the given attachments
Which of the following is a conversion from light energy to chemical energy?
a. turning on a stove to heat dinner
b. growing an apple tree
c. turning on a lamp
d. Turning on a blender
Answer:
A
Explanation:
turning on a stove to heat dinner because it undergoes a chemical reaction to transform into other substance
Growing up a tree is a conversion from light energy to chemical energy.
What is law of energy conservation?Energy can neither be created nor be destroyed , it gets only transferred from one form to another.
What is photosynthesis?The process by which green plants and some other organisms use sunlight to synthesize foods from carbon dioxide and water.In simple words by the process of photosynthesis a tree makes food for itself.What happens when a tree grows?Tree makes food by absorbing the sunlight.The energy of the sunlight is used in making of ATPs in trees.ATP ( Adenosine triphosphate ) is used in various operations in trees.So, the sunlight is light energy which get converted into ATPs , which is chemical energy.
Thus, Growing up a tree is a conversion from light energy to chemical energy.
Learn more about Photosynthesis here -
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What is the critical angle for glass when the refractive index is 1.45
Answer:43.6°
Explanation:
Refractive index=n=1.45
Critical angle=c
n=1/sinc
1.45=1/sinc
Cross multiply
1.45sinc=1
Divide both sides by 1.45
(1.45sinc)/1.45=1/1.45
sinc=0.6897
c=sin(inverse)(0.6897)
c=43.6°
Critical angle is 43.6°
What is the formula for velocity???
Explanation:
divide the distance by the time it takes to travel that same distance, then add your direction to it.
Or change in displacement divided by change in time.
. How does the intensity of sunlight received affect Earth’s temperatures?
Gold, quartz, and talc are minerals. Copper and iron are types of ore. What is the difference between minerals and ores?
A mineral is a non-living, solid substance that can be extracted from the ground. Ore is a type of mineral made up of metals.
An ore is non-living and solid with little value unless it occurs in large amounts, in which case it is a mineral.
O A mineral is a valuable form of ore that can be extracted from the ground
O A mineral is a non-living, solid substance made of elements. Ore is a large deposit of one or more valuable minerals in the ground.
Answer:
A mineral is a valuable form of ore that can be extracted from the ground
Explanation:
Gold, quartz and talc are minerals because they are found in the earth in a valuable form of ore while ores are rocks that contain valuable concentrations of minerals.that can be mined.
An ORE in general term can be said to be a mineral deposit that contains enough Minerals that can be mined in commercial quantities while Minerals are valuable components of an Ore that can be mined ( naturally occurring ) in an ORE.
An ice skater spins at 2.5 rev/s when his arms are extended. He draws his arms in and spins at 10.0 rev/s. By what factor does his moment of inertia change in the process?
Answer:
The moment of inertia decreased by a factor of 4
Explanation:
Given;
initial angular velocity of the ice skater, ω₁ = 2.5 rev/s
final angular velocity of the ice skater, ω₂ = 10.0 rev/s
During this process we assume that angular momentum is conserved;
I₁ω₁ = I₂ω₂
Where;
I₁ is the initial moment of inertia
I₂ is the final moment of inertia
[tex]I_2 = \frac{I_1 \omega_1}{\omega_2} = \frac{I_1*2.5}{10} \\\\I_2 = 0.25I_1 = \frac{1}{4}I_1[/tex]
Therefore, the moment of inertia decreased by a factor of 4
A paint brush is dropped from the top of a tall ladder and free falls to the ground. What changes, if any, would be observed of the velocity and the acceleration of the brush as it falls? Pick the two answers. The velocity increases. The velocity decreases. The velocity remains a constant value. The acceleration increases. The acceleration decreases. The acceleration remains a constant value.
Answer:
Explanation:
As the paint brush is dropped from the top of a tall ladder it started free falling
i.e. velocity of brush increases as it falls down due to the acceleration provided by gravity.
We know acceleration due to gravity is the attraction experienced by the object due to earth attraction
Value of acceleration due to gravity is constant i.e. [tex]9.8\ m/s^2[/tex]
Therefore the correct choice is
velocity is increasing and acceleration is constant
Uranium-235 has 92 protons. How many neutrons does it have?
Answer:
146 neutrons.
Explanation:
plzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz mark me brainliest
Answer: The atomic number of uranium (see periodic table) is 92, and the mass number of the isotope is given as 238. Therefore, it has 92 protons, 92 electrons, and 238 — 92 : 146 neutrons.
Explanation:
10 pts!!!!!! please answer ASAP picture and inscription included
The wavelength of a wave is equal to the distance from one disturbance to
the next and is measured in meters. If the distance between two wave
crests is 2 m, what is the wavelength?
Answer:
2m
Explanation: a crest is a disturbance
Answer:
I think its 4m, but don't quote me. hope I helped
The passage helps the reader to draw conclusions about which character's perspective? ºAlec ºAlice ºAlec's father ºAlec's mother
Answer:
I think it might be A: Alec but tell me if I'm wrong
Explanation:
Answer:
a
Explanation:
i did it on e d g e n u i t y
Which phrases describe all the outer planets’ motion? Select two options.
no rotation
fast rotation
slow revolution
opposite revolution
north to south rotation
Answer:
Fast rotation
Slow revolution
Explanation:
Solar system has 8 planets. 4 inner rocky planets - Mercury, Venus, Earth and Mars and 4 outer gaseous planets - Jupiter, Saturn, Uranus and Neptune. The outer planets have few common features.
They are gaseous. There period of revolution is larger than the inner planets which means that they have slow revolution about the Sun. One day on the outer planets is smaller than the inner planets which means they have fast rotation.
For example, Jupiter has revolves around sun in 11.86 Earth years and rotates about axis in 9.8 Earth hours. Uranus revolves around sun in 84 Earth years and rotates on its axis 17.9 Earth hours.
Answer:
Fast rotation
Slow revolution
Explanation:
did the test
In an inelastic collision, which of the following statements is always true?
[A] Kinetic energy is conserved in the collision.
[B] Momentum is conserved in the collision.
[C] After the collision, the objects always merge into one.
[D] The collision takes more that 1 second to complete.
Answer: A
Explanation:
A
I’m a freshman, I got a 80% in the first quarter, 85% in the second and 70% in the third. I have a 46% in the fourth and 34 total absences in the class. If I fail, will I fail the class or the entire grade
Answer:
you will pass but if your grade become lower and u get more absences you will fail
Ski lift carry people along 150 m cable up the side of a mountain. Riders are lifted a total of 75 m in elevation. What is the ideal mechanical advantage of the ski lift?
Ideal Mechanical Advantage (IMA) can be found by using the formula:
IMA = ID/OD
ID = Input Distance
OD = Output Distance
In the question, we are given:
ID = 150
OD = 75
Now, solve the expression with what we have.
IMA = 150/75
IMA = 2
Therefore, the IMA is 2.
Best of Luck!
explain nuclear fusion briefly
Answer:
Nuclear fusion is the process in which two atomic nuclei are fused together into a larger single nucleus, releasing energy in the process. ... In proton-proton fusion, four hydrogen atoms are fused into a single helium-4 atom, releasing a lot of energy in the process.
Explanation:
IS IT right to the left a b c d
Answer:
c ok
Explanation: right?
Answer:
16
Explanation:
Rafael swings a baseball bat with a force of 25 N. The baseball bat exerts a force of 5 N on the baseball. What is the mechanical advantage of the baseball bat? The mechanical advantage of the baseball bat is
Answer:
0.2
Explanation:
Mechanical Advantage is defined as the ratio of force output with respect to the force input. Thus,
MA = output / input
MA = 5 / 25
MA = 1/5
MA = 0.2
Since this value is less then one. Even though it's tagged a mechanical advantage, in reality it would be mechanical disadvantage.
Therefore, we can say that the mechanical advantage of the baseball bat is 0.2
Answer:
0.2
Explanation:
a man is trying to move a piano by himself, but it will not move, what force must they overcome to start the piano moving?
Answer:
The friction of the piano and the weight
Explanation:
