Answer:
Image formed by a convex mirror is always virtual and erect. When an object is placed at infinity, virtual image is formed at focus and the size of the image is smaller.
도움이되기를 바랍니다!Answer:
convex mirror always form virtual ,erect and diminished image irrespective of the object position.
A swift blow with the hand can break a pine board. As the hand hits the board, the kinetic energy of the hand is transformed into elastic potential energy of the bending board; if the board bends far enough, it breaks. Applying a force to the center of a particular pine board deflects the center of the board by a distance that increases in proportion to the force. Ultimately the board breaks at an applied force of 870 N and a deflection of 1.3 cm .
Required:
To break the board with a blow from the hand, how fast must the hand be moving? Use 0.50kg for the mass of the hand.
Answer:
6.726 m/s
Explanation:
Given that
Applied force, F = 870 N
Distance moves by the force, d = 1.3 cm = 0.013 m
Mass of the hand, m = 0.50 kg
From the given values, first thing is to find the work done by the force. Work done is given as
W = fd.
W = 870 * 0.013
W = 11.31 J
To find the velocity, next we use the formula for finding Kinetic Energy
K.E = 1/2mv²
Where K.E = 11.31
11.31 = 1/2 * 0.5 * v²
22.62 = 0.5v²
v² = 45.24
v = √45.24
v = 6.726 m/s
To break the board with a blow from the hand the speed of the hand will be [tex]v=6.726\ \frac{m}{s}[/tex]
What is speed?
Speed is defined as the distance traveled by any object with respect to the time.
Now it is given that
Applied force, F = 870 N
Distance moves by the force, d = 1.3 cm = 0.013 m
Mass of the hand, m = 0.50 kg
From the given values, first thing is to find the work done by the force. Work done is given as
[tex]W=F\times d[/tex]
[tex]W=870\times 0.013[/tex]
W = 11.31 J
To find the velocity, next we use the formula for finding Kinetic Energy
[tex]KE=\dfrac{1}{2}mv^2[/tex]
Where K.E = 11.31
[tex]11.31=\frac{1}2}\times 0.5\times v^2[/tex]
[tex]0.5v^2=22.62[/tex]
[tex]v^2=45.24[/tex]
[tex]v=6.726\ \ \frac{m}{s}[/tex]
Hence to break the board with a blow from the hand the speed of the hand will be [tex]v=6.726\ \frac{m}{s}[/tex]
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Which material is used to magnetically screen electrical equipment from unwanted magnetic
fields?
A: aluminium
B : copper
C : iron
D :steel
Answer:
B is the answer
Explanation:
Typical materials used for electromagnetic shielding include sheet metal, metal screen, and metal foam. Common sheet metals for shielding include copper, brass, nickel, silver, and tin.
explain any 3 alternating ways of producing electricity
Answer:
to produce electricty three ways you have the water wheel the wind mill and solor panels
Explanation:
PLEASE HELP! I'LL GIVE BRAINLEST
the answer is the first one
You would like a solenoid that is 32 cm long to produce a magnetic field of 0.78 T when it carries a
current of 7.7 A. How many loops should this solenoid have?
Answer:
N = 25795 loops
Explanation:
The magnetic field of a solenoid can be calculated by using the following formula:
[tex]B = \frac{\mu NI}{L}\\N = \frac{BL}{\mu I}[/tex]
where,
N = No. of loops = ?
B = Magnetic Field = 0.78 T
L = Length of solenoid = 32 cm = 0.32 m
I = Current = 7.7 A
μ = permeability of free space = 4π x 10⁻⁷ N/A²
Therefore,
[tex]N = \frac{(0.78\ T)(0.32\ m)}{(4\pi\ x\ 10^{-7}\ N/A^2)(7.7\ A)}\\[/tex]
N = 25795 loops
Consider a taut inextensible string. You shake the end of the string with some frequency, causing a wave to travel down the string. In the questions below, assume you only change one aspect of the system at a time.
1. If you shake the end of the string twice as rapidly (double the frequency), what will happen to the speed of the wave?
2. If you double the tension in the string, what will happen to the speed of the wave?
3. If you shake the end of the string twice as rapidly (double the frequency), what will happen to the wavelength of the propagating wave?
4. If you double the tension in the string, without changing the rate at which you're shaking it, what will happen to the wavelength of the wave?
For each question, choose from the following choices:
a. It will double.
b. It will remain unchanged.
c. It will increase by a factor of √ 2.
d. It will increase by a factor of 4.
e. It will be half as fast/long.
Answer:
Part 1:
Option B is correct (It will remain unchanged).
Part 2:
Option C is correct (It will increase by a factor of √ 2)
Part 3:
Option E is correct (It will be half as fast/long.)
Part 4:
Option C is correct (It will increase by a factor of √ 2.)
Explanation:
Formula we are going to use:
V=f*λ
Where:
V is the speed of Sound
f is the frequency of wave
λ is the wavelength.
The speed of wave , tension and linear density have following relation:
[tex]V=\sqrt{F/\rho}[/tex]
Where:
V is the speed of Sound (Initial)
F is the tension in string (Initial)
[tex]\rho[/tex] is the linear density of string (Constant)
Terms:
V' is the new speed
f' is the new frequency
λ' is the wavelength
Solution:
Part 1:
From [tex]V=\sqrt{F/\rho}[/tex]:
Speed of Sound is independent of the frequency of shaking so speed well remain unchanged.
Option B is correct (It will remain unchanged)
Part 2:
If F'=2F then
[tex]V=\sqrt{F/\rho}[/tex]
[tex]V'=\sqrt{F'/\rho}\\V'=\sqrt{2F/\rho}\\V'= \sqrt{2} * \sqrt{F/\rho}\\V'=\sqrt{2}V[/tex]
Option C is correct (It will increase by a factor of √ 2)
Part 3:
Formula we are going to use:
V=f*λ
Given f'=2f,
Even though frequency is doubled we will keep velocities same. V=V' in order to find the changing wavelength.
V'=f'*λ'
f*λ=f'*λ'
f*λ=2f*λ'
Solving above Equation:
λ'=λ/2
Option E is correct (It will be half as fast/long.)
Part 4:
T'=2T means [tex]V'=\sqrt{2}V[/tex] (From Part 1)
f'=f
Now:
V'=f'*λ'
[tex]\sqrt{2}f*\lambda=f'*\lambda '\\\sqrt{2}f*\lambda=f*\lambda '\\ \lambda '=\sqrt{2}*\lambda[/tex]
Option C is correct (It will increase by a factor of √ 2.)
What is the frequency of a wave traveling at 300,000,000 m/s with a wavelength of .0025 m/cycle ? Please explain good thank you
Answer:
The frecuency is 1.2*10¹¹ Hz.
Explanation:
Wavelength is the minimum distance between two successive points on the wave that are in the same state of vibration. It is expressed in units of length (m).
Frequency is the number of vibrations that occur in a unit of time, that is, how many peaks or valleys are repeated in a unit of time. Its unit is s – 1 or hertz (Hz).
The propagation speed is the speed with which the wave propagates in the medium, that is, it is the magnitude that measures the speed at which the wave disturbance propagates along its displacement. It relates the wavelength (λ) and the frequency (f) inversely proportional using the following equation:
v = f * λ.
In this case:
v= 300,000,000 m/sf= ?λ= 0.0025 mReplacing:
300,000,000 m/s= f* 0.0025 m
Solving:
f= 300,000,000 m/s ÷0.0025 m
f= 1.2*10¹¹ [tex]\frac{1}{s}[/tex] = 1.2*10¹¹ Hz
The frecuency is 1.2*10¹¹ Hz.
Newton's law of universal gravitation is represented by
GMm
where F is the magnitude of the gravitational force
exerted by one small object on another, M and mare
the masses of the objects, and ris a distance. Force has
the SI units kg m/s. What are the SI units of the pro-
portionality constant GP
Answer:
i҈ d҈o҈n҈t҈ k҈n҈o҈w҈ w҈h҈a҈t҈ y҈o҈u҈r҈ s҈a҈y҈i҈n҈v҈ b҈c҈h҈
Answer:
[tex]m^{3}kg^{-1} s^{-2}[/tex]
Explanation:
The speed of light is 3 x 10 m/s.
Calculate the frequency of light that is absorbed the most by the 100m length of fibre.
Give your answer in standard form.
Answer:
[tex]3 \times 10 {}^6[/tex]
1.The focal length is equal to half of the …………….
a. c entre of curvature
b . The radius of Curvature
c. Axis
d. none of the above
2.The point on principal axis at which parallel rays; coming from infinity; converge after reflection is called the …………….
a. Principal Focus
b .Aperture
c .Principal Axis
d. focal length
3.Which of the following best describes the image formed by a plane mirror?
a .Virtual, inverted and magnified
b .Real, inverted and diminished
c. Virtual, erect and the same size as object
d. Real, erect and the same size as object
4.Which of the following best describes the image formed by a convex mirror?
a. Virtual, erect and magnified
Real, inverted and magnified
b .Virtual inverted and diminished
c. Virtual erect and diminished
5.The field of view is maximum for,
a .Plane mirror
b. Concave mirror
c. Convex mirror
d . .Cylindrical mirror
6.Which of the following best describes the image formed by a concave mirror when the object is located somewhere between the focal point (F) and the center of curvature (C) of the mirror?
a .Virtual, erect and magnified
b .Real, inverted and diminished
c .Virtual, erect and diminished
d .Real, inverted and magnified
7.If a man wishes to use a plane mirror on a wall to view both his head and his feet as he stands in front of the mirror, the required length of the mirror ____.
a .is equal to the height of the man.
b .is equal to one half the height of the man.
c. depends on the distance the man stands from the mirror.
d. depends on both the height of the man and the distance from the man to the mirror.
8.Which of the following statements are true of a virtual image?
a Virtual images are always located behind the mirror.
b .Virtual images can be either erect or inverted.
c. Virtual images can be magnified in size, reduced in size or the same size as the object.
d Virtual images can be formed by concave, convex and plane mirrors.
9.Virtual images are not real; thus, you could never see them when sighting in a mirror.
a.Virtual images result when the reflected light rays diverge.
b.Virtual images can be projected onto a sheet of paper.
10.Which of the following statements is/are true of a real image?
.Real images are always located behind the mirror.
a. Real images can be either erect or inverted.
b .Real images can be magnified in size, reduced in size or the same size as the object.
c .Real images can be formed by concave, convex and plane mirrors.
d. Real images are not virtual; thus, you could never see them when sighting in a mirror.
e Real images result when the reflected light rays diverge.
f. Real images can be projected onto a sheet of paper.
Answer:
Explanation:
1.The focal length is equal to half of the …………….
b . The radius of Curvature
2.The point on principal axis at which parallel rays; coming from infinity; converge after reflection is called the …………….
a. Principal Focus
3.Which of the following best describes the image formed by a plane mirror?
c. Virtual, erect and the same size as object
4.Which of the following best describes the image formed by a convex mirror?
a. Virtual, erect and magnified
A car of weight (80 N) been revoked by other car . Find the tnsion force
exerted on that car when it is accelerated by (0.5 m/s2
) .
Answer:
T = 4 N
Explanation:
Given that,
Weight of a car, W = 80 N
We know that,
Weight = mg
80 = 10m
m = 8 kg
If the acceleration of the car is 0.5 m/s², then force becomes,
F = 8 × 0.5
F= 4 N
So, the required tension force is 4 N.
238 U
92 ———————>
The alpha decay of ___ produces an atom with a mass number of...
OA. 234
B. 236
C. 238
D. 240
Answer:
A. 234
Explanation:
An alpha particle is a Helium atom which has a mass number of 4 and atomic number of 2. So, an alpha particle decay cause the mass number to decrease by 4 units.
So 238 - 4 = 234
The answer is A
What do you think most likely cause the differences seen in the two graphs for cold spring and normal wearher
Answer:
The tempature changes, and the envronment chnages because of this, therefore making tempature changes in a graph.
Explanation:
sorry if this isnt good
Temperature variations in a graph occur as a result of changing environmental conditions and changing temperature.
what is temperature ?Temperature is a physical quantity which measures hotness and coldness of a body. Temperature measures the degree of vibration of molecule in a body. Temperature is measured in centigrade (°C), Fahrenheit (°F) and Kelvin (K) in which Kelvin (K) is a SI unit of temperature. Absolute scale of temperature means Kelvin scale of temperature. relation between Kelvin(K) and centigrade (°C), °C= K - 273.15 from equation, 273.15 K means 0 °C, which is freezing point of water (ice). when we give temperature to the body, its molecule or atom absorbs thermal energy and vibrate about their mean position. Amplitude of vibration get increases as we go on increasing temperature and for higher temperature force of attraction between molecules gets weaker. Hence for higher temperature, due to weaken the force of attraction between molecule, solid goes into liquid state. and further increase in temperature liquid goes into gaseous state.
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A child with a mass of 12.32kg weight how much? Show all work including a equation
Answer:
123.2newtons
Explanation:
weight =mass × gravity
w= m×g
gravitational pull is approximately 10N/Kg
w= 12.32kg×10n/kg
=123.2newtons or 12.3N
5. A cart with one fan on It blowing to the left and carrying one block produces the x vs t graph shown If this car were carrying three blocks instead of one, with the
fan still blowing the same direction, what could the x vs t graph look like?
A Graph A
B. Graph B
OC. Graph C
O D. Graph D
Answer:
Graph C
Explanation:
With the same force and more mass, the position in time will still be parabolic
i.e. x = ½at², but the rate of acceleration will be lower so the position curve will be broader.
In an electrical circuit, electrons move from the __________.
A. Negative pole to negative pole B. Negative pole to positive pole
C. Positive pole to positive pole
Answer:
the answer is B from negative pole to positive pole
Priscilla is driving her car on a busy street and Harvey passes her on his motorcycle. What will happen to the sound from his motorcycle after it passes her car?
A.
The frequency of the sound will decrease.
B.
The amplitude of the sound will increase.
C.
The intensity of the sound will increase.
D.
The wavelength of the sound will decrease.
E.
The velocity of the sound will increase.
what is the final velocity of a body if it is moving with 13 m/s in 300 seconds and its acceleration is 30 m/s 2.
?
Answer:
9013m/s
Explanation:
acceleration= v- u/ t
=> at = v-u
=> v = at + u
=> v =30*300+13
= 9013m/s
A 2kg mass moving at a speed of 3 m/s is stopped by a constant force of 15N. How many seconds must the force act on the mass to stop it.
Answer:
t = 0.4 seconds
Explanation:
Given that,
Mass of the object, m = 2 kg
Initial speed of the object, u = 3 m/s
Finally, it stops, v = 0
Constant force applied to the object, F = 15 N
We know that,
Force, F = ma
[tex]F=\dfrac{m(v-u)}{t}\\\\t=\dfrac{m(v-u)}{F}\\\\t=\dfrac{2\times (0-3)}{15}\\\\=0.4\ s[/tex]
So, it will take 0.4 seconds to stop the mass.
as an aid in understanding this problem. The drawing shows a positively charged particle entering a 0.61-T magnetic field. The particle has a speed of 230 m/s and moves perpendicular to the magnetic field. Just as the particle enters the magnetic field, an electric field is turned on. What must be the magnitude of the electric field such that the net force on the particle is twice the magnetic force
Answer:
E = 420.9 N/C
Explanation:
According to the given condition:
[tex]Net\ Force = 2(Magnetic\ Force)\\Electric\ Force - Magnetic\ Force = 2(Magnetic\ Force)\\Electric\ Force = 3(Magnetic\ Force)\\qE = 3qvBSin\theta\\E = 3vBSin\theta[/tex]
where,
E = Magnitude of Electric Field = ?
v = speed of charge = 230 m/s
B = Magnitude of Magnetic Field = 0.61 T
θ = Angle between speed and magnetic field = 90°
Therefore,
[tex]E = (3)(230\ m/s)(0.61\ T)Sin90^o[/tex]
E = 420.9 N/C
Someone who snorts and stop breathing during sleep may be suffering from: a. Catoplexy b. Narcolepsy c. Sleep Apnea d. Insomnia
Answer:
C. Sleep Apnea
Explanation:
Sleep Apnea is when someone who snores and stops breathing while sleeping
Someone who snorts and stop breathing during sleep may be suffering from Sleep Apnea. Hence, option (c) is correct.
What is Sleep Apnea?Breathing repeatedly stops and begins while you sleep, which is a frequent symptom of sleep apnea. Your body may not receive enough oxygen as a result.
There are two different forms of sleep apnea.
When your upper airway is repeatedly closed while you sleep, airflow is reduced or entirely stopped, which is known as obstructive sleep apnea. This kind of sleep apnea is the most prevalent.When your brain fails to deliver the necessary signals for breathing, central sleep apnea develops. Central sleep apnea can be brought on by medical problems that alter how your brain regulates the muscles in your chest and airway.Learn more about sleep apnea here:
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A BODY OF MASS 1 KG HAS WEIGHT 10 N A CERTAIN PLACE . WHAT IS WEIGHT OF 5 KG. PLZ TELL ME IN EXPLAINATION . TROUBLE. I WILL GIVE BRAINLIEST BUT NO LINK
Answer:
50 N
Explanation:
Given that,
A body has a mass of 1 kg that weight 10 N at a certain place. We need to find the weight of 5 kg.
1 kg = 10 N
To find weight of 5 kg, use unitary method such that,
5 kg = (5×10) N
= 50 N
Hence, the required weight is equal to 50 N.
physical sciences grade 11 prescribed experiment 1
topic :the relationship between force acceleration
Answer:
Newton's second law of motion describes the relationship between force and acceleration. They are directly proportional. If you increase the force applied to an object, the acceleration of that object increases by the same factor. In short, force equals mass times acceleration.
Explanation:
A rock falls from a cliff and hits the ground at a velocity of 28m/s. How long did it take to fall?
Answer:
2.8s
Explanation:
=>a = v-u/t
=> t = v - u / t
= 28-0 / 10
= 2.8 s
A cylinder of gas has a frictionless but tightly sealed piston of mass M. A small flame heats the cylinder, causing the piston to slowly move upward. For the gas inside the cylinder, what kind of process is this?
Answer:
isobaric
Explanation:
According to the attached figure, the process would be isobaric as the gas would be expanded at the time when it maintains the constant pressure
The ideal gas law derives
PV = nRT
As the flame is there at the bottom side so atoms or molecules of gas would get heat up slowly also their temperature would be increased. Thus in the case when piston would not be permitted to move so the pressure would rise having maintaining the constant volume and after this the process could be isochronic but in the given case, the piston would be permitted to move slowly upward so that there is a rise in the volume. However, the gas particles would be adjust themselves in order to maintain constant pressure so the given process represent isobaric
helppppppppppppppp.......
what is the final velocity of a body if it is moving with 13 m/s in 300 seconds and its acceleration is 30 m/s 2.
?
Answer:
9013 m/s
Explanation:
hope it helped!!!
A current of 8 A is used to operate a Nespresso coffee machine. Choose the most suitable fuse size from the following
- 3 A
- 5 A
- 13A
-10 A
It needs fuse of size 3A to be operated
Answer: 10 A
Explanation: The 3a and 5 a will blow immediately which would not allow you to use the coffee machine
The 13 a is too high and might lead to damage to the coffee machine or a fire being started
10 A is perfect because its low enough that if their was a power surge it would be blown without damaging anything else and it is high enough to let the coffee machine work without any trouble
If the time period of simple pendulum is doubled then it's amplitude will be
Also explain the answer
Answer:
pls check
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The electrostatic force between two small charged particles is 5.2 x 10^-7 N at a distance of 2 meters. What will be the new force if the distance is
increased to 4 meters apart?
Answer:
[tex]F_2=1.3\times 10^{-7}\ N[/tex]
Explanation:
Given that,
Initial force, [tex]F=5.2\times 10^{-7}\ N[/tex]
distance, d = 2 m
New distance, d' = 4 m
We need to find the new force. The electrostatic force between two charges is given by :
[tex]F=k\dfrac{q_1q_2}{d^2}[/tex]
So,
[tex]\dfrac{F_1}{F_2}=(\dfrac{d_2}{d_1})^2\\\\\dfrac{F_1}{F_2}=(\dfrac{4}{2})^2\\\\\dfrac{F_1}{F_2}=4\\\\F_2=\dfrac{F_1}{4}\\\\F_2=\dfrac{5.2\times 10^{-7}}{4}\\\\F_2=1.3\times 10^{-7}\ N[/tex]
So, the new force is equal to [tex]1.3\times 10^{-7}\ N[/tex].
What are the limitations of sending information using electronic waves
Answer:
The limitations of sending information using electromagnetic waves is that when the electromagnetic waves move outward in all directions, wave transmitters need to be focused to transmit their signals to a single specified location.