Answer:
f = - 0.143 m = - 14.3 cm
Explanation:
First, we will calculate the power of the combination of lenses:
P = P₁ + P₂
where,
P = Power of Combination = ?
P₁ = Power of first lens = - 5D
P₂ = Power of second lens = - 2D
Therefore,
P = - 5D - 2D
P = - 7D
Now, the focal length can be given as:
[tex]f = \frac{1}{P} \\\\f = \frac{1}{-\ 7\ D} \\\\[/tex]
f = - 0.143 m = - 14.3 cm
Negative focal length indicates that combination will act as diverging lens.
When two charged particles are moving toward each other, their velocities decrease until they eventually come to a
stop. What happens afterward? (1 point)
O They remain in the same place without moving.
O They accelerate toward each other.
O they bond and accelerate together.
O They accelerate in opposite directions.
When two charged particles are moving toward each other, they bond and accelerate together.
To find the correct statement among all the options, we need to know about electromagnetic force.
What is electromagnetic force?The force between any two dynamic charged particles is the electromagnetic force. It's a combination of electric force and magnetic force. What does happen, when two charged particles move towards each other?When two charged particles move towards each other, they combine with each other dur to the electromagnetic force. Then they are travelled together as a single particle along the direction of more acceleration.Thus, we can conclude that the option (C) is correct.
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By how many times would the gravitational force between two objects decrease if the distance between the two objects was tripled?
Answer:
If the separation distance between any two objects is tripled (increased by a factor of 3), then the force of gravitational attraction is decreased by a factor of 9 (3 raised to the second power).
I want the answer and that’s all
Answer:
Cuboid?
Explanation:
If you make multiple measurements of your height, you are likely to find that the results vary by nearly half an inch in either direction due to measurement error and actual variations in height. You are slightly shorter in the evening, after gravity has compressed and reshaped your spine over the course of a day. One measurement of a man's height is 6 feet and 1 inch. Express his height in meters, using the appropriate number of significant figures.
Answer:
H = 1.85 m
Explanation:
First, we will convert the height completely into inches. 1 feet contains 12 inches in it. Therefore:
H = (6 feet)(12 inch/1 feet) + 1 inch
H = 73 inches
Now, we will convert this height from inches to meters. 1 inch is equivalent to 0.0254 m. Therefore:
H = (73 inches)(0.0254 m/1 inch)
H = 1.85 m
A bar magnet is held in place while another bar magnet is placed near it. The second bar magnet spins around and
attaches to the first magnet on one end. Which statement is correct about the energy stored in the magnetic field?
(1 point)
O The increase in the energy stored in the system is proportional to the increase in kinetic energy.
O The decrease in the energy stored in the system is proportional to the decrease in kinetic energy.
O The increase in the energy stored in the system is proportional to the decrease in kinetic energy.
O The decrease in the energy stored in the system is proportional to the increase in kinetic energy.
Answer:
o
Explanation:
the increase energy stored in thw system is proportional to the decrease in kinetic energy
The increase in the energy stored in the system is proportional to the decrease in kinetic energy.
What is energy stored in the system ?"The energy stored in the system means the sum of energies of both magnets when second magnet stop spin and stick with first magnet. It is clear that the rotational kinetic energy of second magnet decrease and becomes part of the system. Hence the increase in the energy stored in the system is proportional to the decrease in kinetic energy."
What is kinetic energy ?"Kinetic energy is a form of energy that an object or a particle has by reason of its motion. If work, which transfers energy, is done on an object by applying a net force, the object speeds up and thereby gains kinetic energy."
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A Thomson's gazelle can run at very high speeds, but its acceleration is relatively modest. A reasonable model for the sprint of a gazelle assumes an acceleration of 4.2m/s2 for 6.5s , after which the gazelle CONTINUES at a steady speed.
a. What is the gazelles top speed?
b. A human would win a very short race with a gazelle. The best time for a 30 m sprint for a human runner is 3.6 s. How much time would the gazelle take for a 30 m race?
Answer:
The correct answer will be:
(a) 27.3 m/s
(b) 3.8 s
Explanation:
According to the question:
Acceleration,
[tex]a= 4.2 \ m/s^2[/tex]
Time,
[tex]t = 6.5 \ s[/tex]
(a)
The gazelles top speed will be:
⇒ [tex]V_{max} = at[/tex]
[tex]=4.2\times 6.5[/tex]
[tex]=27.3 \ m/s[/tex]
or,
[tex]= 27 \ m/s[/tex]
(b)
As we know,
s = 30 m
Now,
⇒ [tex]s = \frac{1}{2} at^2[/tex]
or,
⇒ [tex]t=\sqrt{\frac{2s}{a} }[/tex]
On putting the given values, we get
[tex]=\sqrt{\frac{2\times 30}{4.2} }[/tex]
[tex]=\sqrt{\frac{60}{4.2} }[/tex]
[tex]=3.78 \ s[/tex]
or,
[tex]=3.8 \ s[/tex]
Explain the difference between the speed of an Electromagnetic wave and its frequency?
Answer:
Electromagnetic waves differ in their wavelengths and frequencies. The higher the frequency of an electromagnetic wave, the greater its energy. The speed of an electromagnetic wave is the product of its wavelength and frequency, so a wave with a shorter wavelength has a higher frequency, and vice versa.
Explanation:
A thin film of acetone (n=1.25) lies on the surface of a thick piece of water (n=1.30). White light shines down from air onto the thin layer of acetone. Destructive interference occurs for m=3 for a wavelength in air of 600 nm. What is the thickness of the thin film?
Answer:
Explanation:
The wave of light is being reflected two times while going from lower to higher refractive index mediums
So there will be phase reversal two times .
Condition of destructive index
2 μ t = ( 2m+1) λ / 2
Substituting the values
2 x 1.25 x t = ( 2 x 3 + 1 ) x 600nm / 2
2.5 t = 2100 nm
t = 840 nm .
Tritium and helium-3 have the same number of nucleons, but tritium has one proton and two neutrons whereas helium-3 has two protons and one neutron. Without doing a calculation, decide which nucleus has a greater binding energy. Explain. (Select all that apply.)
a. This happens in part because the tritium nucleus has greater Coulombic repulsion.
b. This happens in part because the helium-3 nucleus has greater Coulombic repulsion between nucleons.
c. This happens in part because the tritium nucleus has an extra neutron enhancing the nuclear forces.
d. Helium-3 is more stable.
e. This happens in part because the helium-3 nucleus has fewer neutrons.
f. Tritium is more stable.
Answer:
Tritium is more stable.
This happens in part because the tritium nucleus has an extra neutron enhancing the nuclear forces.
Explanation:
The binding energy is the energy that holds nucleons together in the nucleus. It depends on the number of nucleons present in the nucleus. The greater the number of nucleons, the greater the binding energy.
Also, the more the number of neutrons in a nucleus, the greater the nuclear forces. Helium-3 has only one neutron while tritium has two neutrons. The extra neutron in tritium enhances the nuclear forces hence tritium has a greater binding energy than Helium-3
Tritium is more stable.this happens in part because the tritium nucleus has an extra neutron enhancing the nuclear forces.
What is binding energy?
The binding energy is the energy that holds nucleons together in the nucleus. It depends on the number of nucleons present in the nucleus.
The greater the number of nucleons, the greater the binding energy.Also, the more the number of neutrons in a nucleus, the greater the nuclear forces.
Helium-3 has only one neutron while tritium has two neutrons. The extra neutron in tritium enhances the nuclear forces hence tritium has greater binding energy than Helium-3
Thus tritium is more stable.this happens in part because the tritium nucleus has an extra neutron enhancing the nuclear forces.
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Based on the number on the fuse, what do you think is the maximum current allowed in this circuit?
Answer:
0.3 A
Explanation:
Build the circuit attached. Make sure the switch is turned off as you build the circuit. Set the Selected battery voltage to 10 volts.
A. Based on the number on the fuse, what do you think is the maximum current allowed in this circuit?
Solution:
A fuse is a safety device which is used in circuits for preventing very high currents which can cause overloading or start a fire. A fuse is made up of a low resistance thin piece of metal such that the flow of high current can cause the metal to melt leading to an open circuit. A fuse lets current flow up to a maximum value before it melts and the circuit will be broken.
From the image attached, since the maximum rating of the fuse is 0.3 A, hence the maximum current that can flow through the circuit is 0.3 A.
POSSIBLE POINTS: 4
A sound wave traveling through a solid material has a frequency of 5 hertz. The wavelength of the sound wave is 2 meters. What is the speed of sound in
the material?
50 m/s
1,000 m/s
.
25 m/s
10 m/s
17
18 19 20 21 22 23 24 25 26
19 20 21 2
Ne
12631
MAY
20
0
étv
Answer:
v = fy
speed is equal to frequency × wavelength
5 × 2
[tex]10m.s^{ - 1} [/tex]
Which statement is true about the part of the electromagnetic spectrum that human eyes can detect?
It contains ultraviolet, visible, and infrared light.
It is divided into nine ranges of wavelengths.
It is divided into seven ranges of wavelengths.
It contains only the colors of the rainbow and television waves.
Answer:
A. it contains ultraviolet, visible, and infrared light
Answer:
It is divided into seven ranges of wavelengths
Explanation:
i took the test
what is meant by measurementwhat are the three requirements for selecting a unit of a physical quantity
Answer:
Three requirements for selecting a unit are
1. The unit should be reproducible.
2. It should be possible to define the unit without ambiguity.
3. The value of the unit should not change with space and time.
A physics professor demonstrates the Doppler effect by tying a 900 Hz sound generator to a 1.0- m -long rope and whirling it around her head in a horizontal circle at 100 rpm .
1. What is the difference between the highest frequency heard by a student in the classroom and the initial frequency of the sound generator?
2. What is the difference between the lowest frequency heard by a student in the classroom and the initial frequency of the sound generator?
How far an object moves from a reference point is known as
type your answer...
Answer:
distance
hope it helps
Explanation:
-
Answer please: A box weighing 890 N is pulled along a horizontal surface by means of a string which is at 30° above the horizontal. If the coefficient of kinetic friction is 0.2 and the box is accelerated at 0.8 m/s2, what is the tension in the string?
Answer:
vertical problem:
normal force = weight - string up force
= 890 - T sin 30 = 890-.5 T
horizontal problem:
T cos 30 - .2(890-.5T) = (890/9.81) (0.8)
solve for T
The tension in the string is 257.97 N.
What is meant by tension ?A force that acts along the length of a medium, particularly one conveyed by a flexible medium like a rope or cable, is said to be the tension.
Here,
Weight of the box, W = 890 N
Mass of the box, m = 890/10 = 89 kg
Angle made by the string, θ = 30°
Coefficient of kinetic friction, μ = 0.2
Acceleration of the box, a = 0.8 m/s²
The normal force acting on the box,
Fn = W - Ty
Fn = W - T sin30°
Fn = 890 - T/2
So, the frictional force acting on the box can be given as,
f = μ x Fn
f = 0.2(890 - T/2)
Therefore, the net force acting on the box will be,
ma = Tₓ - f
89 x 0.8 = T cos30° - 0.2(890 - T/2)
0.966 T = 249.2
Therefore, the tension in the string,
T = 249.2/0.966
T = 257.97 N
Hence,
The tension in the string is 257.97 N.
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Q: Winding roads and sharp curves are inherently dangerous
because -
A- You can't see far ahead
B- The speed limit is so slow
C- There may be other vehicles traveling in the
opposite direction
D- You may struggle to stay at the same speed
Answer:
A) you can't see far ahead
D. You may struggle to stay at the same speed.
Winding roads and sharp curves are dangerous because of centrifugal forces while taking curves, whose classic formula is described below:
[tex]F = m\cdot \frac{v^{2}}{r}[/tex] (1)
Where:
[tex]F[/tex] - Centrifugal force, in newtons.[tex]v[/tex] - Speed, in meters per second.[tex]r[/tex] - Radius of curvature, in meters per second.Sharps curves are characterized by low radii of curvature. Given that centrifugal force is inversely proportional to the square radius of curvature and it is opposed to friction force between tires and pavement, if centrifugal force is higher than maximum static friction force, then a car accident could if driver does not decelerate.
Therefore, correct choice is D.
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How does a generator use the effect you noticed in the pickup coil to generate electrical energy? What energy transformations are taking place? Why does a generator make alternating current? What change would have to be made to make direct current?
Answer:
Movement of Electrons in opposite direction of the rotation of the pickup coil leads to the direction of Electrical energy ( Alternating current ).
Explanation:
For a Generator to generate electricity, Electrons that is found in the rotating coil of the Generator will experience some sort of force that makes them to start moving in a direction that is perpendicular to the direction of the rotating/pickup coil found in the Generator.
The conversion of mechanical energy (Rotation of the pickup coil ) to electrical energy takes place in the Generator
The generator makes an alternating current because electrons move in opposite direction of the rotating coil
In other to generate a Direct current using a generator we have to replace the slip rings with commutator.
Pls help! Tysm!!! :D
Answer:
Slowing a bike by applying the brkaes is an xmaple of acceleration
Explanation:
A waterfall is an example of what energy conversion?
Answer:
most common energy transformations is the transformation between potential energy and kinetic energy. In waterfalls such as Niagara Falls, potential energy is transformed to kinetic energy. The water at the top of the falls has gravitational potential energy. As the water plunges, its velocity increases.
Explanation:
Hope this helps you
( I got this from transformation and conservation article)
A bat emits a sound at a frequency of 30.0 kHz as it approaches a wall. The bat detects beats such that the frequency of the echo is 900 Hz higher than the frequency the bat is emitting. The speed of sound in air is 340 m/s at emits a sound at a frequency of 30.0 kHz
(a) What is the speed of the bat?
(b) What is the wavelength of the sound that the bat hears15?
Answer:
a) the speed of the bat is 5.02 m/s
b) the wavelength of the sound that the bat hears is 0.011 m
Explanation:
Given the data in the question;
Frequency of sound emitted by a bat f = 30.0 kHz = 30000 Hz
detected frequency by the bat δf = 900 Hz
speed of sound in air c = 340 m/s
Let speed of sound and speed of bat be c and [tex]v_s[/tex] respectively;
Now, frequency of the sound that is coming from the bat towards the wall due to DROPPLER EFFET will be;
f₁ = ( c / ( c - [tex]v_s[/tex] ) )f ----- let this be equ 1
Also, frequency does not change after deflection. The bat becomes an observer as the dropper is shifted because the reflected sound wave is coming towards it;
Hence, Doppler shifted frequency will be;
f₂ = ( (c + [tex]v_s[/tex] ) / c )f₁
from equ 1, f₁ = ( c / ( c - [tex]v_s[/tex] ) )f, so we substitute
f₂ = ( (c + [tex]v_s[/tex] ) / c ) × ( c / ( c - [tex]v_s[/tex] ) )f
f₂ = ( (c + [tex]v_s[/tex] ) / ( c - [tex]v_s[/tex] ) )f
∴ beat frequency will be;
δf = f₂ - f = ( (c + [tex]v_s[/tex] ) / ( c - [tex]v_s[/tex] ) )f - f
δf = ( 2[tex]v_s[/tex] / c - [tex]v_s[/tex] )f
δf = ( 2[tex]v_s[/tex] / c - [tex]v_s[/tex] )f
2f/δf = c - [tex]v_s[/tex] / [tex]v_s[/tex]
2f/δf = c/[tex]v_s[/tex] - [tex]v_s[/tex] / [tex]v_s[/tex]
2f/δf = c/[tex]v_s[/tex] - 1
c/[tex]v_s[/tex] = 2f/δf + 1
[tex]v_s[/tex] = c / (2f/δf + 1)
now, we substitute in our values;
[tex]v_s[/tex] = 340 / ((2×30000 / 900 ) + 1)
[tex]v_s[/tex] = 340 / (66.6666 + 1)
[tex]v_s[/tex] = 340 / 67.6666
[tex]v_s[/tex] = 5.02 m/s
Therefore, the speed of the bat is 5.02 m/s
b) the wavelength of the sound that the bat hears
frequency of reflected wave is;
f₂ = f + δf = 30000 + 900 = 30900 Hz
λ₂ = c / f₂
we substitute
λ₂ = 340 / 30900
λ₂ = 0.011 m
Therefore, the wavelength of the sound that the bat hears is 0.011 m
What is the net force on a skydiver falling with a constant velocity of 0 m/s downward?
Which is one way to determine whether a reaction was a chemical reaction or a nuclear reaction?
Answer:
Check how much energy was released during the reaction or check for a change in total mass
Which ones are correct??
Answer:
blanket:thermal conductivity
as it conduct heat.
aquarium glass:transparency
as light can be transfered from one side to
another.
3.6 Make innovative suggestions on how you could instill healthy environmental values
in communities.
You could hold rallies which attract a lot of people, they come and you discuss apon making the world a better place and how you want to shape the society.
A student must determine how the mass of a block affects the period of oscillation when the block is attached to a vertical spring. The value of the spring constant is known. The student writes the following experimental procedure.
1. Use an electronic balance to measure the mass of the block.
2. Attach the block to the vertical spring.
3. Displace the block from the system's equilibrium position to a new vertical position.
4. Release the block from rest.
5. Use a meterstick to measure the vertical displacement of the center of mass of the block from the system's equilibrium position to its maximum vertical position above the equilibrium position.
6. Use a stopwatch to measure the time it takes for the system to make ten complete oscillations.
7. Repeat the experiment for different vertical displacements and block masses.
Which of the following steps of the procedure should the student revise to make the determination? Justify your selection.
a. Step 3, because the student must specify whether the new vertical position should be above or below the system's equilibrium position.
b. Step 5, because the meterstick should be used to measure total displacement of the system from its lowest vertical position to its highest vertical position.
c. Step 6, because the stopwatch should be used only to measure the time it takes for the system to make 1 complete oscillation.
d. Step 7, because the experiment should not be repeated for different vertical displacements and block masses.
Answer:
the step that the student should change is step 7
Explanation:
The movement of the spring with block is a simple harmonic type movement, so the procedure proposed by the student is correct, but we must take some care.
Step 3 is important since each movement will be started with similar conditions, also if any displacement is very large we can get out of the linear approximation of Hooke's law, for which we need to know the equilibrium point, since from this point displacements will be measured.
Step 6 should be changed to measure various oscillations to find the average period and thus decrease the error in the time reading.
Step 7 is wrong since the objective of the experiment is to analyze the effect of different masses in the period of oscillation and this step prevents this objective from being carried out.
In conclusion, the step that the student should change is step 7
The step that should be revised to make the determination is c. Step 6, because the stopwatch should be used only to measure the time it takes for the system to make 1 complete oscillation.
Why should step 6 be revised?The student is trying to find the effect of the mass of the block on the period of oscillation in different vertical displacements.
The best way to do this is to measure the time taken per oscillation as this would show a much clearer picture to find the effect of the mass on the oscillation. Timing 10 oscillations will yield incorrect results.
In conclusion, option C is correct.
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An object is moving in a straight line at constant speed. A resultant torce begins to act upon
the object.
State the ways in which the force may change the motion of the object
Answer: The velocity magnitude or the velocity direction chages.
Explanation:
According to Newton's second law of motion, the acceleration of a system moved in same direction and is also directly proportional to the external force which acts on it while inversely proportional to the mass. The formula is: a = F/m
Based on the question, since the object obtains acceleration, then it can be infered that there will be changes in the velocity magnitude or the direction as a result of the motion.
distance travelled/time taken gives?
Answer:
speed
Explanation:
Speed = distance travelled/time taken
Answer: Speed
Explanation:
Speed is defined as the rate of change of the position of an object in a direction. The speed of an object is calculated as the distance travelled divided by the time that is taken.
Speed is regarded as a scalar quantity since it has only direction but doesn't have magnitude. The answer to the above question is speed.