Answer:
C. 9.9 cm
Explanation:
The location of the object, u = 14 cm
The location of the image, v = 5.8 cm
The focal length of the mirror, f = Required
The mirror formula for a convex mirror is given as follows;
[tex]\dfrac{1}{u} -\dfrac{1}{v} = -\dfrac{1}{f}[/tex]
Therefore, we get;
[tex]\dfrac{1}{14 \ cm} -\dfrac{1}{5.8 \ cm} =- \dfrac{41}{406 \ cm} = -\dfrac{1}{f}[/tex]
Therefore;
[tex]f = \dfrac{406 \ cm}{41} \approx 9.9 \ cm[/tex]
The focal length of the mirror, f ≈ 9.9 cm
explain why it is important that the Earths atmosphere absorbs gramma rays emitted by the sun
Answer:
Gamma rays have so much energy they could harm people on Earth. People are protected from gamma rays by Earth's atmosphere. The atmosphere absorbs gamma rays, preventing them from affecting life on Earth. Because gamma rays cannot penetrate Earth's atmosphere, scientists use satellites in space to study them.
Answer:
Explanation:
because gamma rays have so much energy they could harm people on earth
1. Priya is responsible for collecting canned food along three different streets for her school's
annual Thanksgiving Food
Drive. She walks 300 m [N] along Oak Road, 500 m [E] along
Second Street, and then 150 m (S45°W) along Cross Ave. She completes the journey in 10
minutes
a. Draw a scale diagram of her trip.
b. Calculate her total distance, displacement, speed, and velocity.
Answer:
distance = 950 m
displacement = 439.2 m
speed= 1.58 m/s
velocity = 0.732 m/s
Explanation:
A = 300 m North
B = 500 m East
C = 150 m South west
Time, t = 10 minutes = 600 s
(A) The diagram is given below.
(B) Total distance = 300+ 500 + 150 = 950 m
[tex]A = 300 \widehat{j} \\\\B = 500\widehat{i}\\\\C = - 150 (cos 45 i+ sin 45 j) = - 106 \widehat{i} - 106 \widehat{j}\\\\D = A + B + C \\\\D = 394 \widehat{i} + 194 \widehat{j}\\\\D=\sqrt{394^2 +194^2} = 439.2 m[/tex]
Speed = distance / time = 950/600 = 1.58 m/s
velocity = 439.2 / 600 = 0.732 m/s
Một mặt phẳng vô hạn tích điện đều, mật độ σ = 4.10-9 C/cm2, đặt thẳng đứng trong không khí. Một quả cầu nhỏ có khối lượng 8 g, mang điện tích q = 10-8 C treo gần vào mặt phẳng, sao cho dây treo lúc đầu song song với mặt phẳng. Lấy g = 9,8m/s2. Khi cân bằng, dây treo quả cầu hợp với mặt phẳng 1 góc bằng bao nhiêu
Answer:
The angle is 18.3 degree.
Explanation:
A uniformly charged infinite plane, density σ = 4 x 10^-9 C/cm^2, is placed vertically in air. A small ball of mass 8 g, with charge q = 10^-8 C, hangs close to the plane, so that the string is initially parallel to the plane. Take g = 9.8m/s2. When in equilibrium, by what angle is the string hanging the ball to the plane?
surface charge density, σ = 4 x 10^-5 C/m^2
Charge, q = 10^-8 C
mass, m = 0.008 kg
Let the angle is A and the tension in the string is T.
The electric field due to a plane is
[tex]E =\frac{\varepsilon \sigma }{2\varepsilon o}\\\\E =\frac{4\times 10^{-5}}{2\times 8.85\times 10^{-12}}\\\\E = 2.26\times 10^6 V/m \\[/tex]
Now equate the forces,
[tex]T sin A = q E.... (1)\\\\T cos A = m g ..... (2)\\\\divide (1) by (2)\\\\tan A = \frac{10^{-8}\times 2.6\times 10^6}{0.008\times 9.8}\\\\tan A = 0.33\\\\ A = 18.3 degree[/tex]
A lamp is connected to a 230 V mains supply. A current of 4 A flows through the lamp for 30 seconds.
Answer:
The energy dissipated is 27600 J.
Explanation:
Voltage, V = 230 V
Current, I = 4 A
time, t = 30 s
The energy is given by
E = V I t
E = 230 x 4 x 30
E = 27600 J
Does direction matter when determining distance?
yes
no
Answer:
no
Explanation:
ans should be correct
What is the name of the part of the wave that is labeled -
answer: amplitude
the ones who have to watch the video
Answer:
amplitude
Explanation:
sound travel and it amplifies
Tony walks at an average speed of 70 m/min from his home to
school. If the distance between his home and the school is
2100 m, how much time does it take for Tony to walk to
school?
min
Answer:
The answer is 30 min
Explanation:
t = s/v
v = 70 m/min, s = 2100 m
t = 2100/70 = 30 min.
Hope it helps you! ＼(^ᴥ^)／
which type of image is formed by convex lens on a screen?
Answer:
The type of image formed on a screen by a convex lens is real, enlarged and inverted.
Explanation:
A lens can be defined as a transparent optical instrument that refracts rays of light to produce a real image.
Basically, there are two (2) main types of lens and these includes;
I. Diverging (concave) lens.
II. Converging (convex) lens.
A converging lens refers to a type of lens that typically causes parallel rays of light with respect to its principal axis to come to a focus (converge) and form a real image.
Basically, the type of image formed on a screen by a converging (convex) lens is real, enlarged and inverted because it is usually thick across the middle (causing rays of light to converge) but thin at the lower and upper edges.
Question 9 of 10 The data table shows how the amplitude of a mechanical wave varies with the energy it carries. Analyze the data to identify the mathematical relationship between amplitude and energy. Use your equation to find the energy if the amplitude is 8 units. Amplitude Energy 1 unit 2 units 2 units 8 units 3 units 18 units 4 units 32 units
Answer:
A Em
1 ½ K
2 ½ k 4 = 2k
3 ½ k 9 = 4.5 k
4 ½ k 16 = 8k
Explanation:
The total mechanical energy of a simple harmonic movement is constant in time, let's look for the energy at one end of the movement, where the velocity of the body is zero.
Em = U = ½ k x²
at the end x = A
Em = ½ k A²
Let's build a table for the energy and as a function of the amplitudes of the movement
A Em
1 ½ K
2 ½ k 4 = 2k
3 ½ k 9 = 4.5 k
4 ½ k 16 = 8k
as a function of the lowest energy
1 Eo = ½ k
2 4Eo
3 9 Eo
4 16Eo
A steer must eat at least 100 pounds of grain to gain less than 10 pounds of muscle tissue. This illustrates Group of answer choices the second law of thermodynamics. that some energy is destroyed in every energy conversion. the first law of thermodynamics. that energy transformations are typically 100% efficient.
Answer:
the second law of thermodynamics. that some energy is destroyed in every energy conversion.
Explanation:
According to the second law of thermodynamics, energy conversion is never 100% efficient. Some energy is always lost as it is being converted from one form to the other.
The fact that a steer must eat at least 100 pounds of grain to gain less than 10 pounds of muscle tissue shows that not all the energy taken up from the grain is channelled towards building the muscle tissue. Some energy from the grains are lost on the way according to the second law of thermodynamics.
When the motion of one or both of the particles is at an angle to the line of impact, the impact is said to be ________
Answer: Oblique impact
Explanation:
When the motion of one or both of the particles is at an angle to the line of impact, the impact is said to be oblique impact.
On the other hand, when the directions of motion of the two colliding particles are moving along a line of impact, then it's refered to as central impact.
What is the distance to school if it took bob 1 hour to get to it going at the speed of 1 km/h.
Answer:
1 km
Explanation:
Bob travels at one km/h and it takes him one hour to get there.
A planet has a circular orbit around a star. It is a distance of 53,000,000 km from the centre of the star.
It orbits at an average speed of 49,000 km/h.
How many Earth days does it take the planet to orbit the star?
Give your answer to 2 sf.
Answer:
it takes 365 days to revolve around the star(sun)
a ship using an echo sounding device receives an echo from the bottom 0.8 seconds after the sound is emitted. if the velocity of sound in water is 1500m as what is the depth of water?
Answer: depth= 1875m
Explanation: divide t by 2 because its echo it will go and come back thats why we divide it with 2
Then apply formula Depth(d)=velocity (v)/time (t)
Putting values we get ,
d=1500/0.4
d=1875m
The atmosphere of Venus is mostly carbon dioxide, and the atmosphere of the Earth has water vapor. Why are these two gases absent in the atmosphere of the satellite around Saturn called Titan
Answer:
if these gases existed in Titan, this n in solid form, by which its absence in the atmosphere is understood.
Explanation:
Each gas and chemical compound has a defined temperature for changes of state, specifically for the change from gaseous to liquid and from liquid to solid state we have
gas gas → liquid liquid → solid
(ºC) (ºC)
H₂0 (Water) 100 0
CO₂ -56.6 (P> = 5.2 bar) <-56.6
The temperature of the Titan satellite is - 180ºC
From the above, if these gases existed in Titan, this n in solid form, by which its absence in the atmosphere is understood.
que es la energia electrica
Answer:
:) :) :) :) :) :) :) :) :)
Explanation:
:) :) :) .......
When applying an arm sling, the injured arm's hand should be placed in a ________ position in the sling, and above the level of the elbow.
Answer:
The answer is "thumb-up".
Explanation:
The sling often called the arm sling, is a solution for preventing either shoulder or elbow motion during healing. A triangle bandage could be constructed.
A sling is a strong tissue loop that descends from the head to hold the forearm. The armrests in the sling bent also at the elbow.
The injured hand of the forearm should be positioned inside the pin position in the joint above the level of the elbow when putting the forearm sling.
A student places a block on a table and hangs one mass from the block. The student lets the block go and observes the block accelerate toward the end of the table where the mass was located. The student then places the block on the table and hangs a second, larger mass from the opposite end of the block. The block accelerates in the opposite direction from the first trial. What does this experiment demonstrate? Answer:
Magnitude of acceleration
Explanation:
We know that acceleration can increase depending in the force applied on an object, any object with a greater mass will apply a greater force. F = M(a).
This Newton's second law establishes a relationship between the summary of the external force and the acceleration of the body, It is demonstrated with the change in the direction and magnitude of the acceleration in the experiment
Newton's second law establishes a relationship between the net force and the acceleration, according to the expression
∑ F = m a
where ∑F is the sum of the external forces, m the mass and the acceleration of the body
In this case we have an initial situation, the block and a baking mass, therefore an acceleration is created towards the hanging mass given by
W₁ = M₁ g
F = ma
M₁ g = m a
a = [tex]\frac{M_1}{m} \ g[/tex]
where W₁ and M₁ are the weight and the masses of the mass of the body hanging under the acceleration of gravity.
In the second case, perhaps you have two masses, one on each side,
∑ F = W₁ -W₂
∑F = (M₁ -M₂) g
let's use Newton's second law
(M₁ -M₂ ) g = m a
a = [tex]\frac{M_1 - M_2}{m} \ g[/tex]
We can see that in the second case the acceleration depends on the difference of the hanging masses. This is a proof of Newton's second law where the effect on acceleration is due to the sum of all external forces and not of each force individually.
In conclusion with the realization of this experiment demostrate the valid true of Newton's second law
Learn more about Newton's second law here: https://brainly.com/question/19860811
what is measurement?
Find the time taken if the speed of a train increased rom 72km/h to 90km/h for 234km
Answer:
2.89 hours
Explanation:
given :
Vo = 72 km/h
Vt = 90 km/h
S = 234 km
find : the time taken (t) = ?
solution :
2.a.s = Vt² - Vo²
2.a.(234) = 90²- 72²
468.a = 8100 - 5184
= 2916
a = 2916/468 = 6.23 km/h²
so,
t = (Vt-Vo) /a
= (90-72)/ 6.23
= 18/ 6.23
= 2.89 hours
A car starts from rest .If its acceleration is 1.5m/s^2 in 1.5 seconds. then calculate the distance traveled by it.
Answer:1.6875 m
Explanation:
Formula= 1/2 x at^2
Which of the following statements describes how tectonic plates move?
A. They move from the crust to the core.
B. They move from the mantle to the inner core.
C. They move from the inner core to the outer core.
D. They move slowly on top of the mantle.
Answer:
D
Explanation:
The tectonic plates move on the mantle, sort of floating on it as they are part of the crust. When they collide things like mountain ranges form, and big earthquakes happen.
Which of the following is a primary source?
The answer is C :), I think.
A scientific paper is the primary source. A primary source is an item, document, recording, or any other source. Option C is correct.
What is a scientific paper ?Scientific papers are a specific sort of written work with certain characteristics: they are often published in a periodical called a journal, whose sole objective is to publish this type of work.
A primary source is an item, document, recording, or any other source of information created during the period being studied in the academic area of history.
A scientific paper is the primary source.
Hence,option C is correct.
To learn more about the scientific paper, refer:
https://brainly.com/question/1716162
#SPJ2
A system of releases 125kJ of heat while 104kJ of work is done in the system. Calcilate the change om imternal energy (in kJ)
Answer:
DU = 21 KJ
Explanation:
Given the following data;
Quantity of heat = 125 KJ
Work = 104 KJ
To find the change in internal energy;
Mathematically, the change in internal energy of a system is given by the formula;
DU = Q - W
Where;
DU is the change in internal energy.
Q is the quantity of energy.
W is the work done.
Substituting into the formula, we have;
DU = 125 - 104
DU = 21 KJ
scientists are seen very busy in designing the solar power equipments, why?
Answer:
it is because solar energy is the perpetual source of energy and by using it non renewable sources of energy can be conserved for the future
Which plate is the South American plate?
A
B
C
D
Answer: B
Explanation: I think that it is B.
An electrostatic paint sprayer has a 0.17 m-diameter metal sphere at a potential of 25.0 kV that repels charged paint droplets onto the object to be painted, which is grounded (electric potential of 0).
Answer:
[tex]q=0.236uC[/tex]
Explanation:
From the question we are told that:
Diameter [tex]d=0.17m[/tex]
Radius [tex]r=0.17/2=>0.085[/tex]
Potential [tex]E=25.0kV[/tex]
Generally the equation for Potential on spere is mathematically given by
[tex]E=\frac{1}{4 \pi e_0}*\frac{q}{r}[/tex]
Therefore
[tex]q=\frac{25*10^3*0.085}{\frac{1}{4 \pi e_0}}[/tex]
Where
[tex]\frac{1}{4 \pi e_0}=9*10^9[/tex]
Therefore
[tex]q=\frac{25*10^3*0.085}{(9*10^9}}[/tex]
[tex]q=0.236uC[/tex]
An object weighs 2.2 pounds on Earth and has a mass of 1 kilogram. What are the weight and mass of the same object in space where there is no gravity acting on it?
Answer:
Heavier than 2.2 pounds
Explanation:
A car is stationary. It accelerates at 0.8 ms^2
for 10 s and then at 0.4 ms^2
for a further 10 s. Use
the equations of motion to deduce the car’s final displacement. You will have to split the journey
into two parts, since the acceleration changes after 10 s.
Answer:
the car’s final displacement is 60 m
Explanation:
Given;
initail velocity of the car, u = 0
acceleration of the car, a = 0.8 m/s²
time of motion, t = 10 s
The first displacement of the car:
[tex]x_1 = ut + \frac{1}{2} at^2\\\\x_1 = 0 + \frac{1}{2} (0.8)(10)^2\\\\x_1 = 40 \ m[/tex]
The second displacement of the car;
acceleration, a = 0.4 m/s², time of motion, t = 10 s
[tex]x_2 = ut + \frac{1}{2} at^2\\\\x_2 = 0 + \frac{1}{2} (0.4)(10)^2\\\\x_2 = 20 \ m[/tex]
The final displacement of the car;
x = x₁ + x₂
x = 40 m + 20 m
x = 60 m
Therefore, the car’s final displacement is 60 m
What happens in a series circuit when more bulbs are added? (Example: I start out with a complete series circuit with 2 bulbs. Then I add in several more wires and several more bulbs & bulb holders. Now I have a complete series circuit with 5 bulbs).
Answer:
when we add elements in a series circuit the voltage across each element decreases
Explanation:
In a series circuit the current the whole circuit is the same, since there is only one path,
resistance is the sum of the resistance of each element
R_{eq} = ∑ R_i
if we write ohm's law
V = i R_{eq}
we substitute
V = i ∑ R_i
therefore the total voltage is
V = ∑ i R_i = ∑ V_i
With this expression we see that the voltage decreases as we place more elements in the series circuit.
Specifically when we fear two elements the voltage across each element is
V_i = V / 2
when we have 5 elements the voltage across each element is
V_i = V / 5
therefore when we add elements in a series circuit the voltage across each element decreases
