Answer:
focal length :
[tex]{ \tt{f = \frac{r}{2} }} \\ focal \: length = \frac{36}{2} = 18 \: cm[/tex]
From linear magnification:
[tex]{ \tt{ \frac{1}{m} + 1 = \frac{u}{f} }} \\ \frac{1}{9} + 1 = \frac{u}{18} \\ \\ u = \frac{18 \times 10}{9} \\ u = 20 \: cm[/tex]
The object must be at 20 cm
Define SI units. Also mention their importance. SI unit The
Answer:
SI unit is an internationally accepted system and have the same value all over the world .
I don't know the importance sotry
Answer:
SI unit is an internationally accepted system that have same value all over the world.
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.
we
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 %
define simple machine
Answer:
simple machine, any of several devices with few or no moving parts that are used to modify motion and the magnitude of a force in order to perform work. ... The simple machines are the inclined plane, lever, wedge, wheel and axle, pulley, and screw.
The unit of work in terms of Newton and metre is _______
Answer:
Joule
Explanation:
the unit of work is Joule determined by the letter J.
Answer:
JouleExplanation:
Joule is defined as the work done by a force of one newton causing a displacement of one meter. Sometimes, newton-metre (N-m) is also used for measuring work.
What is an effect of continental drift?
Answer: An effect of continental drift is causing tectonic plates resting upon the convecting mantle to move which results in natural disasters like earthquakes, volcanic eruptions, and more.
define one standard kg
Answer:
The mass of platinum iridium rod whose diameter and height are equal an kept at international bureau of weight and measurement in Paris of France is called as one standard kg.
there is a dropping of a coconut of 2kg mass. the speed of the coconut at the moment before it hits the ground is 40m s-1.
calculate the kinetic energy of the coconut at the moment.
We know
[tex]\boxed{\sf K.E=\dfrac{1}{2}mv^2}[/tex]
m denotes to mass v denotes to velocity[tex]\\ \sf\longmapsto K.E=\dfrac{1}{2}\times 2\times 40^2[/tex]
[tex]\\ \sf\longmapsto K.E=40^2[/tex]
[tex]\\ \sf\longmapsto K.E=1600J[/tex]
Why is velocity proportial to pressure?
Answer:
Pressure and velocity are inversely proportional to each other because if pressure increase, the velocity decrease to keep the algebraic sum of potential energy, kinetic energy and pressure constant.
300 ml of a gas at 27°C is Cooled at -3°c at Constant pressure the final volume is plzz answer fast i will mark brainliest
Answer:V₁=300ml
T₁=27°C
V₂=?
T₂= -3°C
as we know
V₁T₁=V₂T₂
By putting values in formula
300ml×27°C=V₂×(-3°C)
300ml×27°C/-3°C=V₂
8100ml/-3=V₂
-2700ml=V₂
or V₂= -2700ml
For Gerald the Human Cannonball, the gunpowder transforms and gives Gerald what type of energy?
Explanation:
The explosives changes Gerald the Human Cannonball and provides him with chemical energy.
Sulfur and carbon serve as fuels, whereas saltpetre serves as an oxidant. Gunpowder has long been employed as a propellant in weapons, artillery, rocketry, and fireworks, as well as a blasting ingredient in quarrying, mine, and road construction.
help me with this one
Answer:
may be d)45°
Explanation:
The capacity of an RD bottle is 100 cc and its mass is 45 g. Find the mass of the bottle when it is filled with a liquid of density 600 kg/m3.
Answer:
The capacity of an RD bottle is 100cc and its mass is 45g. Find the mass of the bottle when it is filled with a liquid of density 600kg/[tex]m^{3}[/tex]
EXPLANATION:
100cc=100[tex]cm^{3}[/tex]
density of liquid=600Kg/ =0.6gm/
so mass of 100cc liquid will be m=d×V=0.6×100=60gm
So mass of bottle filled with liquid will be bottle+liquid=45gm+60gm=105gm
Answer is 105gm.
4 A student says that he has made a magnetic field with some iron filings. What would
you say to him?
Answer:
Yes but no
Explanation:
Here the kid cant say that he has created s magnetic field as iron fillings do not have magnetic properties
Please help me. I need this in a few hours.
Answer:
A) The population of prey is greater than that of predator
Pls help me with this fast. I will mark brainiest
Answer:
a) 70, 95
b) 95-70= 25cc
c) density= mass/volume
102/25
=4.08g/cc
what is the role of the communicator in a dc generator?
A) it keeps the electric current flowing in one direction
B) it keeps the magnetic fields of the permanent magnet steady
C) it causes the magnetic fields of the permanent magnets to reverse
D) it causes the electric current to constantly reverse its direction
Answer:
C
Explanation:
Answer:
A)
Explanation:
it keeps the electric current flowing in one direction
define inertia.mention it's types
Answer:
It is the inability of the body to change by itself its state of rest or uniform motion or direction. Types of Inertia- It is of three types-(1)Inertia of rest (2) Inertia of motion(3) Inertia of direction. (1) Inertia of rest - It is the inability of the body to change by itself its state if rest.
What is 98.907 rounded to 1 significant figure?
The answer to the digits rounded to one significant figure is 100.
Significant figures are the most important figures in a number of digits.
The closer a digit is to the beginning of a number, the more important or significant it is.
But, the rule for rounding up a set of numbers to the first significant or to one significant figure is that:
If the next number is 5 or more, we round up.If the next number is 4 or less, we do not round up.From the numbers 98.907, 9 is the most significant digit followed by 8.
8 is greater than 5 so we should round up by adding one to 9 making the number 100.
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Solve the following numerical problems. a) A load of 400N is lifted up by an effort of 100N. If load distance is 20cm, what will be the effort distance? (Ans: 80cm) b) Two boys, Shrijan having weight 600N and Shrijesh having weight 300N are playing see-saw. If Shrijan is sitting at 2m from fulcrum, where should Shrijesh sit from fulcrum to balance Shrijan?(Ans: 4m) c) A lever of length 1m has been used ttoko lift a load of 600N by applying an effort of 200N. If load is at 20cm from fulcrum, calculate mechanical advantage, velocity ratio and efficiency. (Ans: MA = 3, VR = 4, n=75%) d) Study the figure below and find the value of effort. (Ans: 120N) Muyn) 2.5m 600N 0.5m ? Science and Enyin
Answer:
given,
load = 400 N
effort = 100 N
load distance = 20 cm
we know that ,
E*Ed = L*Ld
=100 N* Ed = 400N * 20 cm
=100N * Ed = 8000N/cm
= Ed =( 8000N/cm ) / 100N
= Ed = 80 cm
b. soln.
given,
load = 600 N
load distance = 2 m
effort = 300 N
effort distance = ?
we know that ,
= E *Ed = L * Ld
= 300N * Ed = 600N * 2 m
= 300N * Ed = 1200N/m
=Ed =( 1200N/m ) / 300 N
= Ed = 4 m
C. soln.
given,
load = 600 N
load distance =20 cm
effort = 200 N
effort distance = ?
M.A = ?
V.R = ?
Efficiency = ?
we know that ,
= E *Ed = L *Ld
= 200N * Ed = 600 N * 20 cm
=200 N *Ed = 12000 N/cm
=Ed = ( 12000 N/cm) / 200 N
= Ed = 60 cm
Also,
M.A = load / effort
=600 N / 200 N
= 3
V.R = Ed/ Ld
= 60 cm / 20 cm
= 4
efficiency = ( M.A / V.R ) 100 %
= ( 3 / 4 ) 100%
= 75 %
d. soln.
given,
load = 600 N
load distance = 0.5 m
effort distance = 2.5 m
effort = ?
we know that ,
= E * Ed = L * Ld
= E * 2.5 m = 600 N * 0.5 m
= E * 2.5 m = 300 N / m
= E = ( 300 N / m ) / 2.5 m
= E = 120 N
the gravitational force between two masses at distance of 2.5×10^6 metre is 250 Newton . what should be distance between them to reduce the gravitational force by half?
Answer:
distance between should be 1.25 × 10^6 m
Explanation:
Force is proportional to separation distance.
[tex]250 \: newtons = 2.5 \times {10}^{6} \: metres \\ ( \frac{1}{2} \times 250) \: newtons = d \\ \\ d = \frac{125 \times 2.5 \times {10}^{6} }{250} \\ d = 1.25 \times {10}^{6} \: metres[/tex]
Answer:
distance between should be 1.25×10^6.
Explanation:
force Is proportional to separation .
mrk above answer branilest .
what is measurement?
Answer:
The comparison of unknown quantity with known quantity is called measurement
Answer:
the size, length or amount of something is a measurement.
Explanation:
Measurements help in daily life and are important to development, accuracy and making decisions.
can ya pls answer dis rq!
Answer:
I don't even know can u tell me how to ask questions
If the box of 500N is placed over the land of area of 2m²,what pressure is experted by the box on the land?
Answer:
250 Pa or N/m^2
Explanation:
Pressure(P)=F/A=500/2=250 Pa or N/m^2
A man stands still on a moving walkway that is going at a speed of 0.2 m/s to
the west. What is the velocity of the man according to a stationary observer?
A. 0.2 m/s north
B. 0.2 m/s west
C. 0.2 m/s South
D. 0.2 m/s east
When,a man stands still on a moving walkway that is going at a speed of 0.2 m/s to the west,then the velocity of the man according to a stationary observer would be 0.2 m/s west,Therefore, the correct answer would be option B.
What is Velocity?The total displacement covered by any object per unit of time is known as velocity. The velocity of an object is depend on the magnitude as well as the direction of the object.
the mathematical expression for velocity is given by
velocity = total displacement /time
The speed and velocity of the object are very different from each other because speed does not depend upon the direction of the moving object but velocity depends on the magnitude of speed as well as the direction of the moving object.
As per given in the problem a man stands still on a moving walkway that is going at a speed of 0.2 m/s to the west therefore from the perspective of a stationary observer the velocity of man would be 0.2 m/s towards West.
Hence the correct options for the problem would be option B.
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Which of the following processes occurs in a battery?
Batteries convert mechanical energy into chemical energy.
Batteries convert chemical energy into kinetic energy.
Batteries convert mechanical energy into electric energy.
Batteries convert chemical energy into electric energy.
Answer:
Batteries convert chemical energy into electric energy.Explanation:
As seen, batteries have chemical energy in them stored which when used in any electronics produces electricity.
Thus, we can conclude that a battery converts chemical energy into electric energy.
The rate of chage of displacement is called __________
Answer:
Velocity is the rate of change of displacement.
What do is mean by environment friendly behaviour?
Two solid cubes have the same Mass but their edges are in the ratio of 4:1. What isthe ratio of their densities?
Let m be the mass of both cubes. If the smaller cube has side length x, then its volume is x ³. The side lengths of the larger cube have length 4x, so the larger cube's volume is (4x)³ = 64x ³, or 64 times as large as the smaller cube.
The first cube has a density of m/x ³, while the larger one has a density of m/(64x ³) = 1/64 m/x ³, so the ratio of densities is (1/64):1, or 1:64 (larger cube to smaller cube).
what is the relation between centre of gravity and stability
Explanation:
tilting it will raise the height of its center of gravity.
Even though you praise your dog for sitting inside on his bed and chewing the bone you gave him, your dog insists on going outside and burying his bone. This is MOST likely an example of:
Answer:
dog
Explanation:
