Answer:
136 m.
Explanation:
From the question given above, the following data were obtained:
Time (t) = 0.80 s
Speed of sound (v) = 340 m/s
Distance (x) =?
The distance of the player from the wall can be obtained as follow:
v = 2x / t
340 = 2x / 0.80
Cross multiply
2x = 340 × 0.80
2x = 272
Divide both side by 2
x = 272 / 2
x = 136 m
Thus, the distance of the player from the wall is 136 m
20 The metal surface of a kettle is hot. What happens to the cool air outside the kettle when it comes into contact with the hot kettle?
A The density of the air decreases and the air falls.
B The density of the air decreases and the air rises.
C The density of the air increases and the air falls.
D The density of the air increases and the air rises.
D. The density of the sir increases and the air rises.
When coming in contact with the kettle, it becomes hot, it expands and rises up, due to lesser density as compared to the surrounding air.
velocity of body in a circular path is variable why
Velocity is directly propertional to dusplacement.Displacement is the shortest dustance between any two points but in a circle dispalcement changes each time as direction is not constant.So, velocity of body in a circular path is variable......
Calculate the efficiency of the following appliances:
1. A radiator that converts 1000) of electrical energy into 900J
of heat energy and 100J of light energy
2. A torch that converts 100J of chemical energy into 35) of
light energy and 65J of heat energy
3. A car that converts 10,000J of chemical energy into 6000) of
kinetic energy and 4000J of heat energy.
4. An energy saver light converts 1,000J of electrical energy
into 7003 of light energy and 300J of heat energy.
5. A speaker converts 100J of electrical energy into 50J of
sound energy and 50J of heat and kinetic energy.
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Answer:
1. The efficiency of the radiator is 90 %
2. The efficiency of the torch is 65 %
3. The efficiency of the car is 40 %
4. The efficiency of the energy saver is 70 %
5. The efficiency of the speaker is 50 %
Explanation:
Efficiency = (Useful energy out ÷ Total energy in) × 100 J
1. Useful energy = 900 J
The total energy in = 1000 J
The efficiency of the radiator = ((900 J)/(1,000 J)) × 100 % = 90 %
2. Useful energy = 65 J
The total energy in = 100 J
The efficiency of the torch = ((65 J)/(100 J)) × 100 % = 65 %
3. Useful energy = 4,000 J
The total energy in = 10,000 J
The efficiency of the car = ((4,000 J)/(10,000 J)) × 100 % = 40 %
4. Useful energy = 700 J
The total energy in = 1,000 J
The efficiency of the energy saver = ((700 J)/(1,000 J)) × 100 % = 70 %
5. Useful energy = 50 J
The total energy in = 100 J
The efficiency of the speaker = ((50 J)/(100 J)) × 100 % = 50 %
The earplug can reduce the sound level to about 18 decibels (dB). What percentage reduction is this intensity?
Answer:
1 x 10 -10 whisper at 1m distance.
Explanation:
Properly fitted ear plugs an reduce noise form 15-30db. Although they are better for low frequencyAnswer:
The change in intensity is 63%.
Explanation:
intensity level = 18 db
Let the intensity is I.
Io = 10^(-12) W/m^2
Use the formula of intensity
[tex]dB = 10 log\left ( \frac{I}{Io} \right )\\\\18 = 10 log\left ( \frac{I}{Io} \right )\\\\1.8 = log\left ( \frac{I}{Io} \right )\\\\\left ( \frac{I}{Io} \right )=63.1[/tex]
So, the change in intensity is 63%.
1. How much heat energy ( Q ) is required to heat 2.0 kg of copper from 30.0 oC to 80.0 oC?
Answer:
38500
Explanation:
I looked it up so it may be wrong
A 43-kg child sits in a massless swing. With what horizontal force must the seat be pulled so that the ropes form an angle of 35o with respect to the vertical
Fx = 295.4N
180°-90°-35°= 55°
F= m(a)
Fy = 43kg(9.81m/s²)
Fy = 421.83N
tan(55°) = 421.83N/Fx
Fx = 421.83N/tan(55°)
Fx = 295.3685458N
What are horizontal and vertical forces?Each component describes the influence of that chain in the given direction. The vertical component describes the upward influence of the force upon Fido and the horizontal component describes the rightward influence of the force upon Fido.
What direction is friction force?The kinetic frictional force is always in the direction opposite to the velocity of the object.
Learn more about horizontal component, refer
https://brainly.com/question/18333367
#SPJ2
How long does it take a car travelling at 80 m/s to decelerate to 18 m/s with an acceleration rate of -16m/s?
We know
[tex]\boxed{\sf a=\dfrac{v-u}{t}}[/tex]
[tex]\\ \sf\longmapsto t=\dfrac{v-u}{a}[/tex]
[tex]\\ \sf\longmapsto t=\dfrac{18-80}{-16}[/tex]
[tex]\\ \sf\longmapsto t=\dfrac{-62}{16}[/tex]
[tex]\\ \sf\longmapsto t=3.8s[/tex]
What is use of lemon Squeezer
Answer:
A lemon squeezer is a small kitchen utensil designed to extract juice from lemons or other citrus fruit such as oranges, grapefruit, or lime. It is designed to separate and crush the pulp of the fruit in a way that is easy to operate.
Answer:
A lemon squeezer is a small kitchen utensil designed to extract juice from lemons or other citrus fruit such as oranges, grapefruit, or lime. It is designed to separate and crush the pulp of the fruit in a way that is easy to operate.
Explanation:
stay safe
how does the siphon work
Answer:
A simple siphon raises water over a crest and discharges it at a lower level.It works coninueasly due to pull of gravity.
Explanation:
Siphons are tubes which draw fluid over the rim of a tank to a lower point. After an initial pressure change to initiate the flow, siphons operate continuously due to the pull of gravity.
Working:
A simple siphon raises water over a crest and discharges it at a lower level. As water flows through a siphon, energy due to pressure and elevation is either lost to pipe friction or converted to velocity energy.
1.
"An estimate of the future value of some variable" is the definition of
A. procurement
B. logistics.
C. a forecast.
D. capacity
Define electric current and drift velocity.
Answer:
Explanation: The voltage or potential difference between two points is defined to be the change in ... I = qnAv relates the drift velocity to the current
4. An aluminium bar weighs 17 kg in air. How much force is required
to lift the bar while it is immersed in gasoline? The density
of aluminium is 170 kg/m' and that of gasoline is 42 kg/m
Explanation:
1ml = 2.7g
Xml = 1.5g
Divide 1.5 by 2.7 to find X.
Obviously, since 1.5 is less than 2.7, you know the answer will be less than 1.
(it’s .5555555555)
s27253129 ,,, message me please, I can't ask you my homework question in the comments :c
To what height, h, would the pendulum bob rise after a single swing if it was being released from the height of 0.80 m
Answer:
0.80 m
Explanation:
Neglecting friction, the total mechanical energy of the pendulum is constant.
E = K + U where K = kinetic energy and U = potential energy.
At its release point of 0.80 m, the pendulum bob has a mechanical energy which is equal to its potential energy, since, its initial kinetic energy is zero. By the time the bob swings to the other end, it has a mechanical energy equal to it initial potential energy since total energy is conserved.
Neglecting friction, the pendulum bob would swing back to its original height of 0.80 m since the total mechanical energy is conserved and at its highest point, it is purely potential energy.
So, the height the pendulum bob swings to after release from a height of 0.80 m neglecting fiction is 0.80 m.
A bucket filled woth water seems light while it sinks into water.Also show their relation using formula
Answer: This phenomenon happens due to upthrust exerted by water.
Explanation:
We know that,
Liquid Pressure is directly proportional to the height of the vertical column in the liquid.(P∝h)
When a bucket filled water is sunk into the water container, there occur difference in the pressure in top and bottom of the water container. Due to this, water exerts an upward force on the bucket filled with water. This is called Uprthrust.
Upthrust on the bucket makes the bucket filled with water lose some of it's weight and causes apparent loss in weight.
Hence, the bucket filled with water seems light while it sinks into water.
why a magnetic compass is used to determine the direction.
Answer:
the magnetic compass is used to determine direction because it is one of the most accurate form of magnet as we already know that a freely suspended magnet always faces towards north direction and south direction
Define electric current and drift velocity.
Answer:
Current- the flow of free charges, such as electrons and ions
Drift velocity- the average speed at which these charges move
Answer:
An electric current is the stream of changed particals, such as electrons & ions, moving through an electrical conductor.
The average velocity attained bycharged partical ,such as electrons,in a material due to electric fields
Please help
25 Points
What Mathematical leads to the formulas for the magnitudes of displacement, velocity, and acceleration?
Answer:
displacement=specific distance
*Velocity=∆displacement/time
*acceleration=∆velocity/time
A 6 kg object's Ug increases by 150 J. What was its change in height?
Please help I don’t understand this and fast please
Answer:
2.5 m
Explanation:
Potential energy is the energy stored in an object as a result of its position relative to other objects
The change in potential energy is given by:
ΔPE = mgh;
where ΔPE is the change in potential energy, m is the mass if the object, g is the acceleration due to gravity and h is the change in height of the object.
Hence given that g = 10 m/s², ΔPE = 150 J, m = 6 kg, hence:
ΔPE = mgh
150 = 6 * 10 * h
150 = 60h
h = 2.5 m
Hence the change in height is 2.5 m
A stone is thrown vertically upwards with an initial velocity of 20m/s. Find the maximum height it reaches and the time taken by it to reach the height (g=10m/s).
Answer:
20m in 2 secs
Explanation:
t=2s
s=20m
hence the maximum height reached by stone is 20m in 2 s
how do u calculate the kinetic energy of a ball of mass 0.25kg being kicked vertically upwards with a speed of 5m/s
Answer:
3.125J
Explanation:
K.E.= 1/2(mass)(velocity)^2
K.E.=1/2(0.25)(5)^2=3.125
What would be the acceleration in a body moving with uniform velocity and why?
Explanation:
The derivative of a constant term is always 0. So the acceleration of the body would be zero. Hence, the acceleration of a body moving with uniform velocity will always be zero.
hope it helps you
a sphere of diameter 6.0
cm is moulded into a thin wire of diameter 0.2 mm calculate the length of the wire in metres
Answer:
V1 = 4/3 pi R^3 = pi D^3 / 6 D = 2 R volume of sphere
V2 = pi r^2 L = pi d^2 L / 4 volume of wire
V2 / V1 = 1 = 3/2 d^2 L / D^3 since volumes are equal
L = 2/3 D^3 / d^2 = 2/3 * 6^3 / .02^2 = 360,00 cm = 3600 m
Hello! I am taking physics H on edge 2021 and if someone could give me the completed Electromagnetic Fields Plan an Investigation student guide/lab report I would be eternally grateful!!!
To create an electromagnetic field, a magnetic and electric field is involved.
An Electromagnetic field planElectromagnetic field consists of both electric and magnetic fields which are produced by human activities through the use of electricity.
With the above definition of electromagnetic field, it's production will involve:
Magnetic field: These fields are created by the magnets.Electric field: These fields are created by electric charges.These fields oscillate in perpendicular planes with respect to each other, and are in phase.
Therefore, to create an electromagnetic field, a magnetic and electric field is involved.
Learn more about electromagnetic field here:
https://brainly.com/question/1594186
Answer:
I need this as well
Explanation:
If the poster got the project, please let me know. I'm struggling on this unit and if you don't want to give out the project, help is appreciated too! thanks
kí hiệu Δs trong vật lí là gì?
Answer:
which language is this
Explanation:
Please help! Will mark Brainliest.
Answer:
18 Nm
Explanation:
if the correct answer
A certain superconducting magnet in the form of a solenoid of length 0.28 m can generate a magnetic field of 7.0 T in its core when its coils carry a current of 80 A. The windings, made of a niobium-titanium alloy, must be cooled to 4.2 K. Find the number of turns in the solenoid.
Answer:
The number of turns in the solenoid is 19506.
Explanation:
Length of solenoid, L = 0.28 m
Magnetic field, B = 7 T
Current, I = 80 A
Let the number of turns is N.
The formula used to find the magnetic field is
[tex]B = \frac{\mu 0N I}{L}\\\\7 = \frac{4 \times 3.14\times 10^{-7}\times N\times 80}{0.28}\\\\N = 19506[/tex]
state Pascal's principle of pressure . please help due tomorrow
Answer:
Pascal's law says that pressure applied to an enclosed fluid will be transmitted without a change in magnitude to every point of the fluid and to the walls of the container.
Explanation:
The pressure at any point in the fluid is equal in all directions.
Explanation:
According to pascal law ,Force applied on bulk of water in a container will be distributed to all molecules of water...
What kind of circuit is the one shown below?
A. Series
B. Parallel
C. Open
D. Combination
That's a parallel circuit. (B)
When current from Point-A reaches the 3-way intersection just to the right of Point-B, it has to make a choice: Either turn left, go through B, and light the lower bulb, or go straight and light the upper bulb.
A circuit that has any "decision" points in it is a parallel circuit. What happens in the real world is: The current splits up. Some of the current that reaches the intersection turns left toward Point-B, and the rest of it goes straight up.
A series circuit is one in which there's only one possible path all the way around. There are no intersections of more than 2 roads, and no electron ever has to decide which way to flow.
An open circuit is one in which there's a break somewhere along the line and electrons can't jump across it. It's like a railroad where a big piece is cut out of the track somewhere. So no trains can travel on that route, and there's no current flowing anywhere in the circuit.
I'm not so sure about a "combination" circuit. I guess you could give that name to a complicated circuit that has some series parts and some parallel-parts. Personally, I'd call that a "series-parallel" circuit. But it really doesn't matter right now. Whatever the word means, the circuit in the picture is definitely not a "combination" circuit.
Answer:
B. Parallel Circuits
Explanation:
A parallel circuit is constructed by connecting the terminals of all the individual load devices so that the same value of voltage appears across each component. In a parallel circuit, charge divides up into separate branches such that there can be more current in one branch than there is in another.
hope i helped
What is the connection of H ions at a ph=2?
Answer:
Explanation:
High concentrations of hydrogen ions yield a low pH (acidic substances), whereas low levels of hydrogen ions result in a high pH (basic substances). The overall concentration of hydrogen ions is inversely related to its pH and can be measured on the pH scale
