(a) a thin layer of vacuum is provided between the two walls of flask, to minimise the heat loss by conduction , because for conduction medium (molecules) is required , but now medium is absent .
.(b) the two walls are silvered to minimise the heat loss by radiation , because a shiny surface is a bad absorber and bad emitter of radiation i.e. good reflector of heat , so prevents the heat exchange between content of flask and surrounding .
(c) the lid of flask is provided with a tight cork stopper to minimise the heat loss by convection , so that convection currents cannot go out .
(d) a plastic (or metal) case is provided with a flask , to protect the flask from physical damage
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5
A cyclist travels 125 km in 5 hours. How fast is the cyclist moving?
Answer:
25 km/h
Explanation:
speed=distance÷time
125÷5=speed
125÷5=25 (then add units)
A wave that can travel through empty space?
A. electromagnetic wave
B. mechanical wave
C. compressional wave
D. transverse wave
Answer: B. Mechanical Waves
Explanation:
While playing hockey, player 1 is speeding down the rink, and doesn't see player 2 standing still on the ice. Player 1
collides with player 2. Explain what happens to the kinetic energy and motion of each player during the collisiort.
Answer:
There are two answers:
When player 1 collided with player 2, player 1's kinetic energy transferred to player 2.
Player 1 could slow down, stop , change direction, or fall, while player 2 would begin moving away from the collision point and possibly fall.
Explanation:
ANSWER QUICK 30 POINTS
What force controls the movement of the planets around the sun, holds together stars grouped in galaxies, and galaxies grouped in clusters? Thoroughly explain your answer, making sure to include an example and describe how this force keeps planets in orbit. Make sure to write at least 3-5 sentences and proper conventions (spelling, grammar, punctuation, etc.) to respond. Put all answers in your own words (pls dont just take my points :( )
Answer:
Gravity creates stars and planets by pulling together the material from which they are made.
Explanation: Thats the only thing i have im stuck on the tga quiz
An inclined plane is used to lift a box into a moving truck. The ramp is 6m long and 1.5m
from the ground. What is the mechanical advantage of the inclined plane?
Given :
An inclined plane is used to lift a box into a moving truck. The ramp is 6 m long and 1.5 m.
To Find :
The mechanical advantage of the inclined plane.
Solution :
Mechanical advantage, M.A of an inclined plane is given by :
[tex]M.A = \dfrac{\text{Length of slope}}{\text{Height of plane}}[/tex]
Putting given values in above equation, we get :
[tex]M.A = \dfrac{6 \ m}{1.5 \ m}\\\\M.A = 4[/tex]
Therefore, the mechanical advantage of the inclined plane is 4.
A ‘can-chiller’ is used to make a can of drink colder. The initial temperature of the liquid in the can was 25.0 °C. The can-chiller decreased the temperature of the liquid to 20.0 °C. The amount of energy transferred from the liquid was 6930 J. The mass of liquid in the can was 0.330 kg.
Calculate the specific heat capacity of the liquid. Give the unit.
Please help :)
Answer:
4200 J/°C/kg
Explanation:
The formula for heat transfer is given by :
Q= m*c*ΔT where;
Q= heat transferred = 6930 J
m=mass of the liquid = 0.330 kg
c= specific heat capacity=?
ΔT = 25-20 = 5.0°C
Applying the values in the formula as;
Q= m*c*ΔT
6930 = 0.330 * c * 5
6930 = 1.65 c
6930/1.65 = c
4200 = c
c= 4200 J/°C/kg
this is a voice recording of the text of a book that you listen rather than read.
Select the true statements.
The interquartile range of A is 1 less than the interquartile range of B.
Including the runs allowed in the tenth game does not cause the spread of the data to change
The median of A is the same as the median of B.
The interquartile range of B is greater than the interquartile range of A.
The median of B is 1 run more than the median of A.
M
Answer:
The true statements are;
The median of A is the same as the median of B
The interquartile range of B is greater than the interquartile range of A
Explanation:
The given parameters are;
The set of the number of runs, A = {1, 4, 2, 2, 3, 1, 1, 2, 1}
The number of runs the pitcher allows in the tenth game = 9 runs
The set of the number of runs allowed in 10 games B = {1, 4, 2, 2, 3, 1, 1, 2, 1, 9}
Rearranging the data, we get
A = 1, 1, 1, 1, 2, 2, 2, 3, 4
B = 1, 1, 1, 1, 2, 2, 2, 3, 4, 9
For the set A, we have;
Q₁ = 1, Q₂ = 2, Q₃ = 2
Therefore, the interquartile range of A = Q₃ - Q₁ = 2.5 - 1 = 1.5
For the set B, we have;
Q₁ = 1, Q₂ = 2, Q₃ = 2
Therefore, the interquartile range of A = Q₃ - Q₁ = 3.25 - 1 = 2.25
Therefore, the correct answers with regards to the two data are;
The median of A is the same as the median of B
The interquartile range of B is greater than the interquartile range of A
The density of molten lava increases as the lava cools and hardens. Give other examples of natural change in density
Answer:
When the water is frozen it turns to ice and the density decreases.
Explanation:
Have A Wonderful Day !!
What is the average speed velocity of the skier in the image?
The average speed of the skier as shown in the image is 2.33 m/s.
What is average speed?Average speed is the ratio of the total distance covered to the total time taken ot cover the distance.
To calculate the average speed of the skier, we use the formula below.
Formula:
S' = ∑d/∑t........... Equation 1Where:
S' = Average speed∑d = Total distance covered∑t = Total time taken to cover the distanceFrom the question,
Given:
∑d = 1+1+1c= 3 min = 3×60 = 180 seconds∑d = 420 mSuibstitute these values into equation 1
S' = 420/180S' = 2.33 m/sHence, the average speed of the skier is 2.33 m/s.
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A car with a mass of 1710 kg kg starts from rest and accelerates to a speed of 13.8 m/s in 13.5 s. Assume that the force of resistance remains constant at 367.1 N during this time.
What is the average power developed by the car’s engine?
Answer in units of W
Answer:
Average Power = 14599.24 W
Explanation:
We know that :
[tex]power = \frac{work \: done}{time} [/tex]
[tex]work \: done \: = force \times displacement \: \cos( \alpha ) [/tex]
Acceleration of car (a) = v - u / t
= 13. 8 - 0 / 13.5
= 1.02 m / sec ^2
Displacement (s) = v^2 / 2a
= 13.8 * 13.8 / 2.04
= 93.35 m
Now,
Resultant force = F (Car) - F (Resistance) = m * a
Force (Car) = m * a + Force (Resistance)
Force (Car) = 1744.2 + 367.1 = 2111.3 N
Work done by Car = Force (Car) * Displacement
= 2111.3 * 93.35 * Cos 0°
= 197089.85 J
Average Power = Work Done / time
= 197089.85 J / 13.5 sec
= 14599.24 W
PLEASE ANSWER ILL GIVE YOU BRAIN!!!!
Answer:
I think the first two one is 70 the second on is 14
I hope this helps if I’m wrong I’m sorry
Explanation:
For cardiovascular exercise, it is important to exercise in your:
1. Resting Heart Rate
2. Target Heart Rate
3. Maximum Heart Rate
4. All of the Above
Answer:
4 target heart rate. is the answer
Explanation:
hope its right
please help me with this question. ill mark you brainlist or whatever you want.
Answer:
Good:
Quarrying creates jobs in areas where there are limited opportunities.
There is a huge demand for the products of quarrying, such as building stone and cement. ...
Quarrying provides income to local councils through taxation.
Good communications are needed for transporting the products of quarrying.
Bad: Quarrying creates pollution from noise and dust.
Heavy traffic causes pollution and congestion on narrow country roads. ...
Quarries create visual pollution and tourists may be deterred by the scars on the landscape.
Explanation:
Answer:
fdhjyegshdrhjfsdffddfnfdhdfkjdfkjkjdfijldfjkdfndfkjhdfbhjfdjdfhhjdfhj
Explanation:
A rocket engine applies a thrust for e fo 450N for 15s. The 2800Kg rocket is travelling 690 m/s before the engine thrust. What is the final velocity of the rocket?
Answer:
692.4m/s
Explanation:
According to Newton's second law;
F = ma
F = m(v-u)/t
m is the mass
v is the final velocity
u is the initial velocity
t is the time
F is the forcr
Given
F = 450N
m = 2800kg
u =690m/s
t =15s
v = ?
Substitute into the formula
450 = 2800(v-690)/15
450×15 = 2800(v-690)
6750 = 2800(v-690)
6750/2800 =v-690
2.4 = v-690
v = 690+2.4
v = 692.4m/s
Hence the final velocity is 692.4m/s
A bus travels 50.0 km/hr for 3.80 hours. The distance traveled will be what?
FOR BRAINLIEST!
Someone draw me a Rube Goldberg Machine.
my friend wore a smart watch to bed,when he woke up in the morning it showed 300 steps taken how did this happen?
Answer:
Your tracker will detect your arm movement and will interpret it as steps so this is what it likely happening. Something similar happens while driving, if you go through a bumpy road or your car has a stiff suspension then this can cause the tracker to detect movement and count it as steps. Usually while driving and if you notice some vibration on your car or steering wheel you can try having your tracker a little bit more tight around your wrist and this will help decrease the amount of steps detected.
Explanation:
(Via AlvaroFitbit)
If a 1-N net force accelerates a l-kg mass at Im/s2, what is the acceleration caused by a net force of 2 N on a 2-kg mass?
Answer:
The acceleration caused by a net force of 2 N on a 2 kg mass is 1 m/s²
Explanation:
The given parameters on an applied force is as follows;
The acceleration given to a 1 kg mass by a 1-N net force = 1 m/s²
According to Newton's second law of motion, the acceleration, "a", given to an object by a force, "F", is proportional to the magnitude of the net force
Therefore, we have;
F ∝ a
The constant of proportionality is given as the mass, "m", of the object, therefore, we have;
F = m × a
The acceleration given to a 2 kg mass by a 2-N net force is given therefore, given as follows;
2 N = 2 kg × a
a = 2 N/(2 kg) = 1 m/s²
The acceleration, "a", caused by a net force of 2 N on a 2 kg mass is a = 1 m/s².
What is the formula for Charles Law?
Answer:
Explanation:
V_{1} = first volume
V_{2} = second volume
T_{1} = first temperature
T_{2} = second temperature
Fig. 2.1 shows a train
Fig. 2.1
The total mass of the train and its passengers is 750000kg. The train is travelling at a speed of 84m/s.
The driver applies the brakes and the train takes 80s to slow down to a speed of 42m/s.
(a) Calculate the impulse applied to the train as it slows down,
impulse =
[3]
(b) Calculate the average resultant force applied to the train as it slows down,
force =
(2)
Answer:
[tex]\mathrm{(a)\:}32,000,000\:\mathrm{Ns},\\\mathrm{(b)\:}390,000\:\mathrm{N}[/tex]
Explanation:
The impulse-momentum theorem states the impulse on an object is equal to the change in momentum of that object. Momentum is given by [tex]p=mv[/tex]. Since mass is constant, the train's change in momentum is:
[tex]\Delta p=m\Delta v=750,000\cdot42=31,500,000=\fbox{$32,000,000\:\mathrm{Ns}$}[/tex](two significant figures).
Impulse is also given as [tex]\Delta p = F\Delta t[/tex], where [tex]F[/tex] is the average force applied and [tex]\Delta t[/tex] is change in time. Since [tex]t[/tex] is given as [tex]80\mathrm{s}[/tex], we have the following equation:
[tex]F\Delta t=\Delta p\\\\F=\frac{\Delta p}{\Delta t},\\\\F=\frac{31,500,000}{80},\\\\F=393,750=\fbox{$390,000\:\mathrm{N}$}[/tex](two significant figures).
whats the result of rounding 52.8015 into five significant figures
Answer:
52.802
Explanation:
"Significant figures" in Mathematics refer to the digits that give accuracy to the value of a measurement. There are specific rules when it comes to determining the significant figures. For example, all non-zero digits are considered significant and zeroes located in-between non-zero numbers are significant. In the number given above, the digit "0" is located between "8" and "1," therefore, it is significant. All the digits above are significant.
The problem is only asking for "five" significant figures. We can do this by counting from the left to the right. By this means, we know that the number will be rounded off to the nearest thousandths, which is "1." The number after 1 is 5, which means that 1 digit will be added to number 1, thus, making the digit into "2." The last digit (5) will then be removed.
Explanation:
five significant of 52.8015=52.801 ..
A projectile is fired horizontally off the top of a cliff with an initial velocity of 30 M/S. It hits the ground after two seconds. What is the initial X component of velocity when the projectile is initially fired? What is the initial y component of the velocity?
Answer:
Initial x component of velocity: 30m/s
Initial y component of velocity: 0m/s
Explanation:
First, draw a diagram of a cliff and the object falling off the cliff as well as the initial velocity listed and the object at the bottom of the cliff with time. The object is fired horizontally, thus the initial velocity in this case 30m/s equals the horizontal initial velocity, there is no initial vertical velocity.
If the object hits the ground in 2 seconds since horizontal velocity is not affected by any other forces it will move at constant speed horizontally. However, vertically there is a gravitational force acting on the projectile converted from the potential energy of it's height. we know the gravitational constant g=-9.8m/s^2, and we can use the kinematic equation Δy=v0(t)+1/2at^2 to find the Δy(change in height of the projectile), as v0y=0, Δy=1/2at^2, a=9.8m/s^2 and t=2 seconds
thus Δy=19.6m≈20m
hope this helped
The initial X component of velocity when the projectile initially fired is 30m/s. The initial Y component of velocity when the projectile initially fired is 0m/s.
What are equations of motion?There are three equation of motions that can be used when motion of the object is under constant acceleration and on a straight path.
The vertically there is a gravitational force acting on the projectile converted from the potential energy of it's height.
The gravitational constant g =-9.8m/s^2,
we can use the equation of motion
Δy = v0(t) + 1/2at^2
The initial horizontal velocity of the projectile, Vₓ = 30 m/s
The time of the motion of the projectile, t = 2 s
The horizontal distance traveled by the projectile is given by the range of the projection as;
X = Vₓt
X = 30 x 2
X = 60 m
Thus the horizontal distance traveled by the projectile is 60 m
Hence, The initial X component of velocity when the projectile initially fired is 30m/s. The initial Y component of velocity when the projectile initially fired is 0m/s.
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Which of these will cause the highest tides? A. when the Sun, Moon and Earth are in a straight line B. when all of the planets are on the same side of the Sun C. when the Sun, Earth, and Moon form a right angle D. when there are high speed winds caused by seasonal changes
Answer:
A. when the Sun, Moon and Earth are in a straight line
Explanation:
The highest tide is formed when the sun, moon, and also the earth are in alignment. This high tide is known as spring tides.
Spring tides happen when we have a new moon or a full moon. With the earth, sun and moon aligning. We have lunar and solar tide forming a reinforcement with each other causing high tides or extreme tides. we have collectively, their gravitational pull on water of the earth to become stronger
At the height of 800 meters, a skydiver falls from an airplane flying horizontally at 40 m/sec. What is the horizontal distance of the skydivers travel before they "hit" the ground?
Answer:
The horizontal distance traveled by the skydiver is 510.8 m.
Explanation:
Given;
height of fall, h = 800 m
initial velocity of the airplane, u = 40 m/s
The time to fall to the ground is calculated as;
[tex]t = \sqrt{\frac{2h}{g} } \\\\t = \sqrt{\frac{2 \times 800}{9.81} }\\\\t = 12.77 \ s[/tex]
The horizontal distance or range of the motion is calculated as;
R = ut
R = 40 m/s x 12.77 s
R = 510.8 m
Therefore, the horizontal distance traveled by the skydiver is 510.8 m.
Which energy source contributes least to global warming?
A. Coal
B. Natural gas
C. Solar
D. Petroleum
Solar energy source contributes least to global warming. Hence option C is correct.
What is renewable and non renewable energy sources ?Renewable energy is a energy from a source that is not exhausted or depleted when used. Solar energy or wind energy are examples of the renewable energy source. as wind and solar power is abundantly present everywhere in the environment, it can not be exhausted after its over use.
Non-renewable energy comes from sources that will be exhausted or will not be replenished after its use. Fossil fuels: coal, petroleum, and natural gas are the examples of the non renewable energy sources . Coal is the main element in fossil fuels.
Solar energy is abundantly available in the entire solar system. It is renewable energy source, it has no bad effect on the environment and global warming.
Hence option C is correct.
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Does someone have hamster name recommendation (girl hamster)
Explanation:
Lola
Or Jasmine
Or lucy
Or Nightingale
Or Sugarcane
Or Polly
Or Heather
Some names I like!
What can always be said about a negatively-charged ion?
A negatively-charged ion always has more neutrons than protons
A negatively-charged ion always has more electrons than protons
A negatively-charged ion always has more protons than electrons
A negatively-charged ion always has more protons than neutrons
Answer: A negatively-charged ion always has more electrons than protons
Explanation:
First, we know that the elementary negative charge is the electron, while the positive one is the proton. Such that both have the same charge in magnitude, but a different sign. Such that if we have the same number of electrons and protons in an atom, the charge of this atom will be neutral.
And an ion is an atom with a different number of electrons and protons, so the charge of the atom is not neutral.
Then if we have a negatively-charged ion, the charge of this atom is negative. Then we must have a larger number of electrons (the negative ones) than protons (the positive ones)
Then the correct option is:
A negatively-charged ion always has more electrons than protons
An object is subject to a 84 Nm torque about a point when a
21 N of force is applied to a second point along the object's
length. How far apart are the two points
Answer:
d = 4[m]
Explanation:
Torque in physics is defined as the product of force by distance. This way you can use the following equation to calculate the torque.
[tex]T=F*d[/tex]
where:
T = torque [N*m]
F = force [N]
d = distance [m]
Now replacing in the equation above.
[tex]84=21*d\\\\d= 4[m][/tex]
The air temperature is 70 degrees, and the relative humidity is 90%. Which conclusion can be made?(1 point)
The air holds little water vapor and is relatively dry.
The amount of water vapor in the air is 90% of what the air can hold.
The dew point temperature is 90% of the air temperature.
The temperature must rise in order for air to become saturated with water vapor.
Answer:
The amount of water vapor in the air is 90% of what the air can hold.
Explanation:
The answer is A
Answer: The answer is B: The amount of water vapor in the air is 90% of what the air can hold