Answer:
B. in both directions until the temperature is equal in the water and the air
Explanation:
When a warm body is in contact with a cool body , there is exchange of heat energy in both sides until there is attainment of equilibrium temperature . At this temperature both the body attains equal temperature . Initially rate of heat radiated by warm body is more than that from cool body , but after attainment of equilibrium , the rate becomes equal to each other . This is called dynamic equilibrium .
Hence option B is correct .
First you lift an object from the floor onto a shelf. Then you move the object back to the floor. do you perform the same amount of work each time? Explain.
Patrick the pole vaulter is running with a 20m long pole toward a 10m long garage with doors at each end. Patrick is running so fast that to an observer O in the rest frame of the garage, the pole appears only 10m long (i.e. the pole would just fit inside the garage).
a. In the frame of observer O, how fast is Patrick running?
b. The observer O closes very quickly the doors on both ends of the garage just as Patrick and the pole are inside, and then immediately opens them again so that Patrick can run out on the other end. However, according to Patrick, the garage is moving towards him and is only 5m long. How can Patrick and his 20m pole possibly make it through without hitting a door?
Answer with Explanation:
We are given that
Length of pole(l0)=20 m
Length of garage(l)=10 m
a. We have to find the speed by which the Patrick is running.
We know that
[tex]l=l_0\sqrt{1-\frac{v^2}{c^2}}[/tex]
Substitute the values
[tex]10=20\sqrt{1-\frac{v^2}{c^2}}[/tex]
[tex]\frac{10}{20}=\sqrt{1-\frac{v^2}{c^2}}[/tex]
[tex]\frac{1}{2}=\sqrt{1-\frac{v^2}{c^2}}[/tex]
[tex]\frac{1}{4}=1-\frac{v^2}{c^2}[/tex]
[tex]\frac{v^2}{c^2}=1-\frac{1}{4}=\frac{3}{4}[/tex]
[tex]v^2=0.75c^2[/tex]
[tex]v=0.87c[/tex]
b.
l0=10 m
[tex]l=10\sqrt{1-\frac{3}{4}}[/tex]
[tex]l=5m[/tex]
Hence, the length of garage appear to him=5 m long.
An ideal monatomic gas initially has a temperature of 300 K and a pressure of 5.79 atm. It is to expand from volume 420 cm3 to volume 1450 cm3. If the expansion is isothermal, what are (a) the final pressure and (b) the work done by the gas
Answer:
a) The final pressure is 1.68 atm.
b) The work done by the gas is 305.3 J.
Explanation:
a) The final pressure of an isothermal expansion is given by:
[tex] T = \frac{PV}{nR} [/tex]
[tex] T_{i} = T_{f} [/tex]
[tex] \frac{P_{i}V_{i}}{nR} = \frac{P_{f}V_{f}}{nR} [/tex]
Where:
[tex]P_{i}[/tex]: is the initial pressure = 5.79 atm
[tex]P_{f}[/tex]: is the final pressure =?
[tex]V_{i}[/tex]: is the initial volume = 420 cm³
[tex]V_{f}[/tex]: is the final volume = 1450 cm³
n: is the number of moles of the gas
R: is the gas constant
[tex] P_{f} = \frac{P_{i}V_{i}}{V_{f}} = \frac{5.79 atm*420 cm^{3}}{1450 cm^{3}} = 1.68 atm [/tex]
Hence, the final pressure is 1.68 atm.
b) The work done by the isothermal expansion is:
[tex] W = P_{i}V_{i}ln(\frac{V_{f}}{V_{i}}) = 5.79 atm*\frac{101325 Pa}{1 atm}*420 cm^{3}*\frac{1 m^{3}}{(100 cm)^{3}}ln(\frac{1450 cm^{3}}{420 cm^{3}}) = 305.3 J [/tex]
Therefore, the work done by the gas is 305.3 J.
I hope it helps you!
A fox locates its prey under the snow by slight sounds rodents make. The fox then leaps straight into the air, and then burrows its nose into the snow to catch its meal. If a fox jumps up to a height of 79 cm, calculate (a) the speed at which the fox leaves the snow, and (b) how long the fox is in the air. Ignore air resistance.m/s:s:You throw a baseball directly upward at time t = 0 at an initial speed of 12.9 m/s. What is the maximum height the ball reaches above where it leaves your hand? At what times does the ball pass through half the maximum height? Ignore air resistance and take g = 9.80 m/s2.Maximum height:Earlier time at half maximum height:Later time at half maximum height:
Answer:
1.a) 3.93 m/s
b) 0.80 s
2. a) 8.49 m
b) 0.39 s
Explanation:
1. a) The speed at which the fox leaves the snow can be found as follows:
[tex] v_{f}^{2} = v_{0}^{2} - 2gH [/tex]
Where:
g: is the gravity = 9.80 m/s²
[tex]v_{f}[/tex]: is the final speed = 0 (at the maximum height)
[tex]v_{0}[/tex]: is the initial speed =?
H: is the maximum height = 79 cm = 0.79 m
[tex] v_{0} = \sqrt{2gH} = \sqrt{2*9.80 m/s^{2}*0.79 m} = 3.93 m/s [/tex]
Hence, the speed at which the fox leaves the snow is 3.93 m/s.
b) The time at which the fox reaches the maximum height is given by:
[tex]v_{f} = v_{0} - gt[/tex]
[tex]t = \frac{v_{0} - v_{f}}{g} = \frac{3.93 m/s}{9.80 m/s^{2}} = 0.40 s[/tex]
Now, the time of flight is:
[tex] t_{v} = 2t = 2*0.40 s = 0.80 s [/tex]
2. a) The maximum height the ball reaches is:
[tex] H = \frac{v_{0}^{2} - v_{f}^{2}}{2g} = \frac{(12.9 m/s)^{2}}{2*9.80 m/s^{2}} = 8.49 m [/tex]
Then, the maximum height is 8.49 m.
b) The time at which the ball passes through half the maximum height is:
[tex]y_{f} = y_{0} + v_{0}t - \frac{1}{2}gt^{2}[/tex]
Taking y₀ = 0 and [tex]y_{f}[/tex] = 8.49/2 = 4.245 m we have:
[tex] 4.245 m -12.9m/s*t + \frac{1}{2}*9.80m/s^{2}*t^{2} = 0 [/tex]
By solving the above quadratic equation we have:
t = 0.39 s
Therefore, the time at which the ball passes through half the maximum height when the ball is going up is 0.39 s.
I hope it helps you!
Which of the following best describes what were wrong with the scientists study
Using your knowledge on personal care products, how does sunscreen
lotion protect your skin from the damaging effect of ultraviolet rays?
Explain why of x-rays and gamma rays are commonly used in
radiotherapy.
Answer:
Ultraviolet rays from sun are very harmful from skin and can cause sunburn and skin diseases especially ultraviolet B rays. A sunscreen lotion act as a protection barrier on the skin that restrict the direct contact of UV rays with skin and filter the harmful rays to enter the skin.
Radiotherapy is a medical therapy use to treat cancer. Radiotherapy commonly uses x-rays and gamma rays because they are high-energy particles or waves that kills or destroys the cancer cells.
Sunscreen lotion is able to filter this damaging ultraviolet radiation and prevent it from damaging the skin.
The sun reaches us from outer space brings ultraviolet rays to us. Ultraviolet rays are known to have some damaging effects on the skin. One way to protect our skin from this damaging ultraviolet rays is to use sunscreen lotion which is able to filter this damaging ultraviolet radiation and prevent it from damaging the skin.
X-rays and gamma rays are used in radiotherapy because they are light energy rays which are able to penetrate and destroy malignant cells in the body.
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Take 47 points. Hurry Someone save me just look the picture
Answer:
suppose buying pizza for a work party leads to positive morale and to the work being done in half the time. Pizza is the independent variable, Work speed is the dependent variable, The mediator, the middle man without which there would be no connection, is positive morale. Denaturation, in biology, the process of modifying the molecular structure of a protein. Denaturation involves the breaking of many of the weak linkages, or bonds (e.g., hydrogen bonds), within a protein molecule that is responsible for the highly ordered structure of the protein in its natural (native) state.
Explanation:
hope this helps have a good rest of your day :) ❤
Explanation:
HW1. For example, suppose buying pizza for a work party leads to positive morale and to the work being done in half the time. Pizza is the independent variable, Work speed is the dependent variable, The mediator, the middle man without which there would be no connection, is positive morale.
HW2. The word denature means to render food unpleasant or dangerous to consume, it is denatured by adding a substance known as a denaturant. Aversive agents—primarily bitterants and pungent agents—are used to produce an unpleasant flavor.
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A spider accelerates from a standstill to 5m/s in 10s. What is its acceleration?
Answer:
Acceleration = 0.5m/s²
Explanation:
Given the following data;
Final velocity = 5m/s
Time = 10 seconds
Since the spider started from rest, its initial velocity is equal to 0m/s
To find the acceleration;
In physics, acceleration can be defined as the rate of change of the velocity of an object with respect to time.
This simply means that, acceleration is given by the subtraction of initial velocity from the final velocity all over time.
Mathematically, acceleration is given by the equation;
[tex]Acceleration (a) = \frac{final \; velocity - initial \; velocity}{time}[/tex]
[tex]a = \frac{v - u}{t}[/tex]
Where,
a is acceleration measured in [tex]ms^{-2}[/tex]
v and u is final and initial velocity respectively, measured in [tex]ms^{-1}[/tex]
t is time measured in seconds.
Substituting into the equation, we have;
[tex]a = \frac{5 - 0}{10}[/tex]
[tex]a = \frac{5}{10}[/tex]
Acceleration = 0.5m/s²
The resistivity of a material is 2x10-3Ωm. What is the conductivity\n
Answer:
Conductivity, [tex]\sigma=500\ (\Omega-m)^{-1}[/tex]
Explanation:
Given that,
The resistivity of a material, [tex]\rho=2\times 10^{-3}\ \Omega-m[/tex]
We need to find the conductivity of the material.
We know that the reciprocal of resistivity is called conductivity.
[tex]\sigma=\dfrac{1}{\rho}\\\\\sigma=\dfrac{1}{2\times 10^{-3}}\\\\\sigma=500\ (\Omega-m)^{-1}[/tex]
So, the conductivity of the material is [tex]500\ (\Omega-m)^{-1}[/tex].
Can someone help me grasp the concept of solving this please
Answer:
Q= m × c × change in tempQ= 1000 cal/kg × C Q= (5kg) × (1000 ) × (100-13) Q= 435000Hence 4.35 × 10^5 Ask any questions!I also do quizzes and exams if your interested!A tennis player hit a .057-kg ball with a force of 40 N. The duration of the force was .05 s.
a star produces energy by? ( a p e x )
A. absorbing and releasing the matter of other stars.
B. rotating quickly on its axis.
C. reflecting energy from nearby stars.
D. creating helium from hydrogen in its core.
A star produces energy by creating helium from hydrogen in its core (option D).
How does a star produce energy?A star is a luminous celestial body, made up of plasma (particularly hydrogen and helium) and having a spherical shape.
Nuclear fusion is the energy-producing process in stars. The "proton-proton chain," a series of events that turns four hydrogen atoms into one helium atom, dominates this process for the majority of stars.
Nuclear fusion is the combining of the nuclei of small atoms to form the nuclei of larger ones, with a resulting release of large quantities of energy.
Hydrogen atoms fuse in the core of the star to form a helium atom, which generates the energy for the star.
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You drive on Interstate 10 from San Antonio to Houston, half the time at 75 km/h and the other half at 106 km/h. On the way back you travel half the distance at 75 km/h and the other half at 106 km/h. What is your average speed (a) from San Antonio to Houston, (b) from Houston back to San Antonio, and (c) for the entire trip
Answer:
Explanation:
a ) from San Antonio to Houston let distance be d km .
Average speed = total distance / total time
time = distance / speed
Total time = (d / 2 x 75 ) +( d / 2 x 106 )
= .0067 d + .0047 d
= .0114 d
Average speed = d / .0114 d = 87.72 km /h
b ) from Houston back to San Antonio
Total time = (d / 2 x 106 ) +( d / 2 x 75 )
= .0047 d + .0067 d
= .0114 d
Average speed = d / .0114 d = 87.72 km /h
c )
For entire trip :
total distance = 2d
total time = 2 x .0114 d
Average speed = 2 d / 2 x .0114 d
= 87.72 km /h .
calculate the peak voltage of a mains supply of 240Vrms.
Marquette King, formerly of the Denver Broncos, is practicingkicking off using a kicking holder with the ball on the ground.For one of the kicks the ball reaches a height of 90.6 m andlands on the ground 53 yds (48.5 m) away. Find the magnitudeof the initial velocity given by his kick to the ball. Treat airresistance as negligible. Hint: Even though the horizontal andvertical motions are independent, there is a quantity that iscommon to both of them.
Answer:
Explanation:
Maximum height reached = 90.6 m . Range = 48.5 m
. Let u be the initial velocity at angle α .
Horizontal range is covered by horizontal component of u .
Vertical height is achieved by vertical component
v² = u² sin² α - 2gh , t is time taken to attain maximum height .
0 = u² sin² α - 2 x 90.6 x 9.8
u² sin² α = 2 x 887.88 -------( 1 )
Range R = u² sin2α / g
48.5 = 2 u² sinα . cos α / 9.8
u² sinα . cos α = 237.65 ----------------------------- ( 2 )
( 1 ) / ( 2 )
Tan α = 2 x 887.88 / 237.65 = 7.47
α = 82⁰
u² sin² α = 2 x 887.88
u² sin² 82 = 2 x 887.88
u² = 1812
u = 42.56 m /s
Can someone help me answer please
Answer:
4=Conduction by convection by radiation.
Explanation:
Hope it will help you! It may be short but I don't know how to write it in blank aafai milayera lekha Hai blanks ma
Points A, B, and C lie along a line from left to right, respectively. Point B is at a lower electric potential than point A. Point C is at a lower electric potential than point B. What would best describes the subsequent motion, if any, of a positively-charged particle released from rest at point B?
Answer:
Please see below as the answer is self-explanatory.
Explanation:
If the potential at B is lower than A, and the potential at C is lower than B, this means that there is an electric field, directed from A to C.If a positively-charged particle is released at rest at point B, it will be accelerated by the electric field (which is a force per unit charge, so it produces an acceleration) in the same direction than the field (because it is a positive charge) towards point C.3. One effective method for coping with change is using:
Recall
Revisitation
Reminiscence
Reminding
Cope up with changes is significant in everyone's life. One of the suitable way is to remind ourselves that we can withstand with the changes.
What is reminder?Reminding a thing that is important to anyone or ourselves until we do it a better way. Thinking past time and wasting time is just ridiculous. Because we must cope up with the current scenario and build up our mental strength.
Our lives are constantly impacted by changes. Change is a constant, uncontrolled aspect of life that has an impact on our work ethics and routines.
Anything that changes may have major or little repercussions. As a result, since the extent of change's first consequences is uncertain, we must refrain from discriminating against it.
Organizations can effectively use change as a tool. Without change, people would be hesitant to form fresh perspectives and ideas. They wouldn't be able to respond to daily obstacles and would become inert in their work and their roles.
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In a game of ice hockey, you use a hockey stick to hit a puck of mass 0.16 kg that slides on essentially frictionless ice. During the hit you exert a constant horizontal force on the puck that gives it an acceleration of 75 m/s2 for a fraction of a second. During the hit, what is the magnitude of the horizontal force that you exert on the puck
Answer:
12N
Explanation:
given- mass, acelation
Fnet=ma= .16kg*75m/s2
Fnet=12 N only force no friction given.
I need helpp! This is urgent tomorrow is the duedate
Answer:
The Force that resists the motion of one object moving relative to another is Friction. Kinetic Friction Resists the motion of Moving objects, while Static friction keeps the objects from moving.
A mass of 10. kg is placed on the end of a 0.50-meter pendulum. What is the period of the pendulum?
Answer:
T = 1.41 seconds
Explanation:
Given that,
The mass placed in the pendulum, m = 10 kg
The length of the pendulum, l = 0.5 m
We need to find the period of the pendulum. The relation for the period of the pendulum is given by :
[tex]T=2\pi \sqrt{\dfrac{l}{g}} \\\\T=2\pi \sqrt{\dfrac{0.5}{9.8}} \\\\T=1.41\ s[/tex]
So, the time period of the pendulum is 1.41 seconds.
For anyone that needs the correct answer without POS trolls:
The answer is 1.4 s
Thank me later :)
Please give a step by step explanation: 30 points up for grabs.
Answer:
Honestly, I don't know ¯\_(ツ)_/¯
Explanation:
A steel ball (mass = 50 grams) and a plastic ball of the same dimensions (mass = 10 grams) are dropped from the same height at the same time. Which of the following will occur? (ASSUME NO AIR RESISTANCE)
a. the plastic ball will hit the ground before the steel ball hits the ground
b. the steel ball will hit the ground before the plastic ball hits the ground
c. the steel ball and the plastic ball will hit the ground at the same time
Are you better off in an accident where the hood is
deformed or where the car is not damaged at all but
bounces backward?
Answer:
you would be better off if the car bounced backwards
Explanation:
because if the hood was dismembered than you have a high chance of very bad injury but if it is just bounced back you would have less chance of getting hurt if properly sitting and seat belted.
Two soccer players kick a soccer ball back and forth along a straight line. The first player kicks the ball 11 m to the right to the second player. The second player kicks the ball to the left weakly; it only moves 2.7 m before stopping. (Consider the right to be the positive direction. Where applicable, indicate the direction with the sign of your answer.)
(a) What is the total distance that the ball moved?
m
(b) At the end, what is the displacement of the ball (from the first player)?
m
Answer:
a) 13.7 m
b) 8.3 m
Explanation:
a)
The total distance traveled by the ball is just the sum of the distances traveled after being kicked by the first player (11 m.) plus the distance moved after being kicked by the second player (2.7 m), independent of the direction of the movement:[tex]d = d_{1} + d_{2} = 11.0 m + 2.7 m = 13.7 m (1)[/tex]
b)
The total displacement of the ball, is just the difference between the final and initial position, by definition.If we choose the origin to be in the place that the ball is kicked by the first player,[tex]x_{o} = 0 (2)[/tex]
The final position along the x-axis, is just the distance traveled to the right (11 m) minus the distance traveled to the left (considering the right to be the positive direction), 2.7 m:[tex]x_{f} = x_{1} - x_{2} = 11.0 m - 2.7 m = 8.3 m (3)[/tex]
⇒ Δx = xf - x₀ = 8.3 m - 0 m = 8.3 m
How is light energy different from both sound and heat energy?
A.
Sound energy is a wave.
B.
Light energy can exist independently of matter.
C.
Heat energy can radiate from an object.
D.
Light is more energetic when its frequency is higher.
Answer:
B. Light energy can exist independently of matter.
Explanation:
In science, matter can be defined as anything that has mass and occupies space. Any physical object that is found on earth is typically composed of matter. Matter are known to be made up of atoms and as a result has the property of existing in states.
Generally, matter exists in three (3) distinct or classical phases and these are;
I. Solid.
II. Liquid.
III. Gas.
Light energy is different from both sound and heat energy because light energy can exist independently of matter.
Generally, we know that light energy is a type of electromagnetic waves and as such do not require a medium of propagation for it to travel through a vacuum of space where no particles exist. For example, light energy from distant galaxy of stars and the sun.
However, both sound and heat energy are mechanical waves which are highly dependent on matter for their propagation and transmission.
Use g = 9.80 m/s2 (down]
1. What velocity does a freely falling object reach after 4.0 s if it starts from rest?
The velocity of the freely falling object reached after 4.0 s is equal to 39.2 m/s.
What is the equation of motion?A relation can be established between the velocity of the body and acceleration of the body when the body is moving along a straight line with uniform acceleration. The distance traveled by the body in a specific time has expressed a set of equations called equations of motion.
The first equation of motion can be expressed as follows:
v = u + at
Where u is the initial velocity, v is the final velocity and a is the acceleration and t is the time of the object.
Given, the acceleration of the falling object, g = 9.8 m/s²
The initial velocity of the object, u = 0, and the time = 4 sec
The velocity of the object after time, t = 4 sec.
v = (0) + (9.80)× (4)
v = 39.2 m/s
Therefore, the velocity of the falling object will be 39.2 m/s after 4 seconds.
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____made up of glucose and fructose and found in plants.
1.Xylose
2.Maltose
3.Lactose
4.Sucrose
Answer:
1.Lactose
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An object with a mass of 5 kg is traveling ata velocity of 20 m/s. How much kinetic energy does it have?
Answer:
KE = ½mv²
KE = ½5kg×(20m/s)²
KE = ½5kg×400m²/s²
KE =5kg×200m²/s²
KE = 1000joules
The degree of relationship between two or more variables is _________.