Answer:
A positive charge placed in an electric field will tend to move in the direction of the electric field lines and a negative charge will tend to move opposite to the direction of the electric field lines.
One way to remember this is that there is one velocity, and so the thumb represents it. There are many field lines, and so the fingers represent them. The force is in the direction you would push with your palm. The force on a negative charge is in exactly the opposite direction to that on a positive charge.
Explanation:
Answer:
The force of the negative particle direction is East.
What can the magnetic fields influence?
A) It can cause objects to be pulled towards the magnet and pushed away from the magnet.
B) It only causes a repel force between the magnets.
C)It cause only an attraction force.
Explanation:
Magnetic fields are areas where an object exhibits a magnetic influence. The fields affect neighboring objects along things called magnetic field lines. A magnetic object can attract or push away another magnetic object. You also need to remember that magnetic forces are NOT related to gravity.
Name any three things that cause soil pollution
Answer:
garbage , polluted water dam, unexpected dust particle
3.
If the specific heat of iron = 0.46 J/g Cº, how much heat is needed to warm 50 g of
iron from 20° C to 100° C?
Answer:
1.84 kJ (kilojoules)
Explanation:
A specific heat of 0.46 J/g Cº means that it takes 0.46 Joules of energy to raise the temperature of 1 gram of iron by 1 Cº.
If we want to heat 50 g of iron from 20° C to 100° C, we can make the following calculation:
Heat = (specific heat)*(mass)*(temp change)
Heat = (0.46 J/g Cº)*(50g)*(100° C - 20° C)
[Note how the units cancel to yield just Joules]
Heat = 1840 Joules, or 1.84 kJ
[Note that the number is positive: Energy is added to the system. If we used cold iron to cool 50g of 100° C water, the temperature change would be (Final - Initial) or (20° C - 100° C). The number is -1.84 kJ: the negative means heat was removed from the system (the iron).
How much physical activity should an adult have each week?
A.
60 minutes per day, 7 days a week
B.
30 minutes per day, 7 days a week
C.
60 minutes per day, 5 days a week
D.
30 minutes per day, 5 days a week
Please select the best answer from the choices provided.
A
B
C
D
The physical activity should an adult have each week is "60 minutes per day, 5 days a week". The correct answer is option C.
What is WHO?WHO stands for the World Health Organization. It is a specialized agency of the United Nations responsible for international public health. The WHO is headquartered in Geneva, Switzerland, and works in partnership with national governments and other organizations to promote health, keep the world safe, and serve the vulnerable. The organization's primary objective is to ensure that people can enjoy the highest possible level of health, regardless of their race, religion, or socioeconomic status. The WHO's work includes providing leadership on matters critical to health, setting norms and standards, promoting health research and evidence-based practice, and providing technical support to countries.
Here in the Question,
Option A, "60 minutes per day, 7 days a week," and option B, "30 minutes per day, 7 days a week," both suggest that physical activity should be performed every day of the week. While daily physical activity is beneficial for overall health and well-being, the WHO recommendation allows for two days of rest or lighter physical activity per week, which can help prevent injury and allow for recovery.
Option D, "30 minutes per day, 5 days a week," suggests a lower amount of physical activity than the WHO recommendation. While 30 minutes of moderate-intensity aerobic physical activity per day can provide some health benefits, it may not be enough to achieve significant improvements in cardiovascular health, muscular strength, and flexibility.
Therefore, Option C, "60 minutes per day, 5 days a week," is the correct answer as it aligns with the WHO recommendation for adults to engage in at least 150 minutes of moderate-intensity aerobic physical activity per week.
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A fairly efficient steam turbine engine fired by coal is used to drive an electric generator. The generator operates between 2100°C and 385°C.
(a) Determine the maximum possible efficiency of the engine.
Answer: 72.3 %
Formula:
e = 1 - (Tc / Th) = 1 - (Qc / Qh) = ( W / Qh)
Explanation: Unsure??
(b) The engine absorbs 1.15 105 J from the hot reservoir every second. If the actual efficiency of the engine is 40.3%, determine the mechanical power the engine delivers.
Answer: 46 kW
Explanation:
Energy absorbed by the engine (J) * actual efficiency of the engine (%) = mechanical power the engine delivers (kW)
How does 1 - (385/2100) = 72.3 % ?
What do I Plug in to make e = 72.3 %
Use kelvin not celsius
C + 273 = K
This will fix my problem of the equation not making sense.
A very light rod 40cm long is pivoted at the centre. A weight of 50N is placed at one end. Where is the place to put a weight of 200N in order that the rod is in equilibrium?
Hi there!
We can go about this problem using a summation of torques.
In order to ensure the rod is in equilibrium, we must satisfy the condition:
Στ = 0
Since the rod is "very light", we can disregard its mass.
The equation for torque is:
τ = rFsinθ
In this instance, the torques are the weights of the objects and their distance from the pivot.
As the rod is 40 cm, the pivot is at 20 cm. Also, the torques must sum up to 0, so:
0 = rF1 - rF2
r1F1 = r2F2
0.20(50) = r2(200)
Solve:
10 = r2(200)
r2 = 0.05 m = 5 cm
The 200N weight must be put at a distance of 5 cm from the OTHER SIDE of the pivot in order to balance the rod.
What is the horizontal acceleration of a ball that is launched horizontally with a velocity of 5. 6 m/s? â€""9. 8 m/s2 0 m/s2 5. 6 m/s2 9. 8 m/s2.
The horizontal acceleration of a ball that is launched horizontally is equal to: B. 0 [tex]m/s^2[/tex]
Given the following data:
Horizontal velocity = 5.6 m/sTo determine the horizontal acceleration of a ball that is launched horizontally:
Acceleration can be defined as the rate of change of velocity with respect to time. In Physics, the acceleration of an object or body is calculated by subtracting its initial velocity from the final velocity and dividing by the time.
Mathematically, acceleration is given by the formula;
[tex]Acceleration = \frac{V\; -\;U}{t}[/tex]
The projectile motion of an object launched horizontally has a constant velocity and as such its horizontal acceleration would be equal to zero meter per seconds square ([tex]0\;m/s^2[/tex]).
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Who does more work- a man who lifts a large box from the ground into the back of a truck, or a man who puts the same box on a trolley and wheels it up a ramp into the truck?
Answer: the first man does more work than the other
Explanation: because the second man has tool a trolley and a ramp to help him make his job easier
In the experiment shown below, which is greater, the force of gravity on the pith balls (Fg) or the electrostatic force between them (Fq)?
Answer:
Electronic force
Explanation:
Maybe because its warmer and may have more force
I need help ASAP pls be right sn know what your doing
Answer: Biology
This is because the first two make no sense and physics is the study of matter and energy. Biology, however, studies the life of plants and animals, which can be used for renewable energy.
whats 1+0 n3rje'hefruhhhhhhhhhhhhhhhhhhhhhhhhtrrrrrrrrrrrrr
Answer:
1
Explanation:
cause 1+0=1
What electromagnetic wave is used in nuclear research and mineral exploration?.
The electromagnetic wave used in nuclear research and mineral exploration are gamma rays.
Electromagnetic waves refer to those rays that are found in the electromagnetic spectrum. They are collectively called light. Electromagnetic waves are used for different purposes.
Gamma rays are useful in nuclear research especially in identifying decaying radionuclides. Also, gamma rays are used for geologic mapping, mineral exploration, and identification of environmental contamination.
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easy one - giving brainly if correct.
Gas.
HOPE YOU GET 100!
A skydiver that has a weight of 1050 N. jumps from a plane at an altitude of 5000 m. How much work is performed on the skydiver?
Answer:
5.25MJ
Explanation:
Considering the weight of the skydiver constant over the descent -ie, the acceleration of gravity not decreasing as you go up the earth surfice, the work is simply the product of the two:
[tex]w= \vec F\cdot \vec x = Fx = 1050\times 5000 = 5,250,000 = 5.25MJ[/tex]
A football player kicks the ball with an initial velocity of 28.3 m/s at an angle of 60° above the horizontal. The ball is in the air for a total of 5.00 s before hitting the ground. Ignoring air resistance, what would be the ball's horizontal displacement?
Hi there!
Since the ball is directed 60° above the horizontal, we must use its HORIZONTAL component to find its displacement.
We can take the cosine to do so:
vcosθ = 28.3cos(60) = 14.15 m/s
Since the ball is in the air for 5 sec, we can use the following equation:
displacement = velocity · time (d = vt)
Plug in the values:
d = 14.15 · 5 = 70.75 m
You are carrying a heavy bag of sand, not realizing it has a hole in the bottom. As you are walking, the bag becomes easier to carry. Explain this situation using Newton's Second Law
Newtons second law of motion states that, the force acting on a body is directly proportion to the mass times the acceleration of the body
The equation use to represent the second law is given below
F = ma
Explanation of the situation: When the heavy bag was being carried initially , the full weight will be felt, but as the bag keeps losing more sand the weight will be reducing and so the force the person carrying the bag will feel will become less and this will go on as more sand keeps dropping off the bag
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Which statement or phrase best describes the currently accepted model of the atom?
1. Atoms are extremely small spheres which cannot be divided into smaller particles.
2. Atoms are like plum pudding with most of the mass being positively charged and evenly spread throughout the atom and electrons randomly placed throughout this mass.
3. Atoms contain a very small, dense, positively charged nucleus with electrons circling the nucleus
in defined paths called orbits.
4. Atoms contain a very small, dense, positively charged nucleus with electrons moving around the
nucleus in the electron cloud.
Answer:
4
Explanation:
Answer:
i am pretty sure that it is 4
A group of waves is propagated at a speed that is ________ the speed of the individual waves in deep water.
A crane lifts a 10000 N load through a distance of 30mins in 40s calculate work done
Given,
Force = 10,000 N
Distance = 30 m
Time = 40 s
Work done = force × distance
Work = 10,000 × 30
Work = 300,000 J
______
꧁✿ ᴿᴬᴵᴺᴮᴼᵂˢᴬᴸᵀ2222 ✬꧂
The work done on the object is equal to the power it experiences which is equal to 735 watts.
What is work done?Work done is defined as the product of force applied and the distance over which the force is applied on the object. Work is done on an object when a force is applied to an object and the object is moved through a particular distance.
The time rate of doing work is called as power, which is designated by the symbol P. It is measured in the units of watts, where one watt is equal to one joule energy applied per second time.
Work done on an object is equal to the force (F) multiplied by the distance d in the direction of the force. Where, time interval is Δt.
P = W/Δt = F × d/Δt = m × g × h/Δt = 100 × 9.8 × 30 / 40
Power = 735 watts
The power of the object is 735 watts.
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What is normal air pressure
Standard sea-level pressure, by definition, equals 760 mm (29.92 inches) of mercury, 14.70 pounds per square inch, 1,013.25 × 103 dynes per square centimetre, 1,013.25 millibars, one standard atmosphere, or 101.325 kilopascals.
Now explore friction force. Set the piece of plastic or wood on the table and push it steadily across the tabletop using your fingertip. Note how much opposition to your push you feel. Repeat the steps, but this time push the piece of plastic or wood across a rug, carpet, or piece of fabric. If you’re using fabric, be sure to secure the fabric so it doesn’t move. How does the opposition to the motion on the tabletop compare with that of the rug, carpet, or fabric? (I don't wanna do this so can someone answer this please)
Answer: If there is a higher friction, the opposition force is higher so that it can reduce our speed. So, a factor that affects friction is the roughness or smoothness of the surface of the object. In comparison of the table with the fabric, the fabric will have a more opposition force. As the surface of the fabric is usually rougher than the surface of a smooth table. As there is more friction on a fabric, we will feel more opposition force on our finger tip.
Hope it helped! :>
the free body diagram shown above is for a 5 kg box on a rough surface being pulled to the right at a constant speed by a string that is at an angle of 30° above the horizontal. the coefficient of kinetic friction between the box and the surface is 0.30. the tension in this string is most nearly:
The tension in the string pulling the box is most nearly 17 N.
The given parameters;
mass of the box, m = 5 kginclination of the string, θ = 30°coefficient of kinetic friction, μ = 0.3The tension on the string is calculated by applying Newton's second law of motion as follows.
[tex]\Sigma F = ma[/tex]
at constant speed, acceleration, a, = 0
[tex]\Sigma F = 0\\\\T_x - \mu F_n = 0\\\\Tcos(\theta) - \mu F_n = 0\\\\Tcos(\theta)= \mu F_n\\\\T = \frac{\mu F_n}{cos(\theta)} \\\\T = \frac{0.3 \times 5 \times 9.8}{cos(30)} \\\\T = 16.97 \ N\\\\T \approx 17 \ N[/tex]
Thus, the tension in the string pulling the box is most nearly 17 N.
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Some houses are built with very thick walls. Explain how these walls help to keep the houses
warm in the winter.
Thicker walls provide more materal for .......
to travel through from the inside to outside, so the
is less, keeping the houses warmer.
(2 marks)
Answer: It banks night-time cool to bring temperatures down in the day, and warms up over the course of the day and then releases the warmth at night. Thick walls or exposed solid floors can provide thermal mass. The shape of buildings matters too, and the orientation around each other so that the wind moves in particular ways. Hope this helps, tell me if I need to add anything. :))
A potted plant falls from the window of an apartment building. It falls for 2.0
s and then hits the ground. What is the speed of the plant just before it hits
the ground? Assume only gravity is acting on it.
A)20 m/s
B) 9.8 m/s
C) 2.0 m/s
D) 4.9 m/s
Answer:
D) 4.9 m/s
Explanation:
Speed of Object in Free Fall
s = Rate of Acceleration, Due to Gravity × Length of Time
s = 9.8 × 2.0
s = m/s (Round Up to The Nearest Whole Number)
--
m/s = 9.8 ÷ 2.0 = 4.9 m/s
An astronomer examines an emission line spectrum for a star from data recorded by a spectroscope. There are four lines: two in the blue region, one in the green region, and one in the red region of the spectrum. How does the spectrum obtained from the spectroscope help the astronomer?
The characteristics of the atomic spectrum allow to find the result so that the measured lines help the astronomer is:
The astronomer can identify the gases that are present in stars using emission lines.
The emission spectrum is the emission of light due to the atomic transition in atoms, consequently the spectrum of each chemical element is unique.
The astronomer was able to identify the chemical elements that are in stars by their emission spectrum.
In the case presented there are two lines in the blue region, a line in the green region and a line in the red region. We know that the most abundant element in stars is hydrogen.
Hydrogen has a series of well-defined spectral lines, the series that is in the visible part of the spectrum is called the Balmer series and is composed of the lines in the table.
Color wavelength (nm)
red 656.3
blue 486.1
violet 434.1
The second element in quantity in stars is helium, which has the spectrum given in the table and in the attached.
color wavelength (nm)
Red 667.8
orange 587.6
green 501.6
Blue 492.2
Blue 447.1
The astronomer compares his measured spectrum with the spectra of these two gases and finds that the element he is measuring is helium.
In conclusion, using the characteristics of the atomic spectra, we can find the result to help the astronomer with the measured lines is:
The astronomer can identify the gases that are present in stars using emission lines.
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Answer:b
Explanation:
did it
Select the correct answer.
What represents the value of the second-best alternative that a person gives up when making a choice?
OA. marginal spending
ОВ.
marginal benefit
OC. opportunity cost
OD. marginal cost
The answer should be opportunity cost
Find the volume of this figure.
4 dm
2 dm
3 dm
Answer:
4×2×3= 24dm^3
.......................
How many boxes of potatoes does the Mayflower need if each person gets 3 potatoes a day?
How many burlap bags of cabbage need to be stored if each person will receive 4 cups of cooked shredded cabbage per day?
Using the appropriate arithmetic operation, the amount of potatoes and cabbage require for the voyage are 19998 and 26664 respectively.
Number of men = 47Number of women = 32Number of children = 22 Number of voyage daysTotal number of passengers = (47 + 32 + 22) = 101
1.)
If each person gets 3 potatoes per day :
Number of potatoes needed per day = (3×101) = 303
Number of potatoes needed for entire voyage = (303 × 66) = 19998 potatoes.
2.)
If each person gets 4 cabbage per day :
Number of cabbage needed per day = (4×101) = 404
Number of cabbage needed for entire voyage = (404 × 66) = 26664 cabbages.
Hence, the number of cabbage needed for the voyage would be 26664 cabbages.
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1. if the work done to move a box to a distance of 6 metres equals 120 joules. calculate the force
2. Calculate the potential energy of a book with a mass of 1.5 kg placed on top of a shelf with a height of 2 m.
(Knowing that the acceleration due to gravity = 10 m/s2
).
3. What is meant by?
The potential energy of an object = 20 joules.
Explanation:
1. W = F x D
F = W/D
F = 120/6 = 20Newton
2. P. E = mgh
P. E = 1.5x10x2 = 30Joules
3. It means that the energy the body possesses at that point is 20Joules
How much energy must be transferred out of the system as heat q to lower its temperature to 0∘c?.
Answer:
2.20 × 104 J
Explanation:
How much energy must be transferred out of the system as heat Q to lower its temperature to 0?C? ANSWER Q = 2.20 x 10^4. Cooling Power of P is 36.6 W.