The answer is D
I took the quiz lol
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.
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).
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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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. :))
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
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.
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
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! :>
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
Find the volume of this figure.
4 dm
2 dm
3 dm
Answer:
4×2×3= 24dm^3
.......................
Name any three things that cause soil pollution
Answer:
garbage , polluted water dam, unexpected dust particle
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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easy one - giving brainly if correct.
Gas.
HOPE YOU GET 100!
An object is in equilibrium. Which force vector diagram could represent the force(s) acting on the object
Answer:
velocity and force
Explanation:
Velocity and force vector diagram represent the force acting on the object.
What is vector diagram?Diagrams are called vector diagrams to use a vector arrowhead to show the magnitude or direction of a vector quantity. The velocity of an item in motion could be represented in vector diagrams. A vector diagram might be used, for instance, to depict the motion of an automobile traveling down a road.
What is force?A force was an influence that will have the power to alter an object's motion.
Therefore, velocity and force vector diagram represent the force acting on the object.
To know more about vector and force.
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Plzzzzzzzzz
Help
Will give brainlessness
Answer:
1. A
2. A; distance is scalar, displacement is vector
3. C ; position is on the y-axis
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
A group of waves is propagated at a speed that is ________ the speed of the individual waves in deep water.
whats 1+0 n3rje'hefruhhhhhhhhhhhhhhhhhhhhhhhhtrrrrrrrrrrrrr
Answer:
1
Explanation:
cause 1+0=1
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]
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
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.
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.
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
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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How to calculate angular velocity.
Answer:
Answer below
Explanation:
We can rearrange this statement to get the angular velocity equation: = r v / |r|2, where all of these variables are vectors and |r| is the radius's absolute value. The angular velocity is really a pseudovector with a direction perpendicular to the plane of rotational movement.
The rotating movement of bodies is described by angular velocity. It determines how quickly they rotate around a central point. Rotations may be divided into two categories. The first explains the motion of an object's centre of mass around a certain point in space, which is referred to as an origin. Planets orbiting the Sun, for example, or an automobile exiting a roadway are two instances.
The first angular velocity equation is similar to the linear velocity equation: = (2 - 1) / t = / t, where 1 and 2 are two values of angles on a circle, and is the difference between them. t is the time it takes for the angle to shift. As you can see, there is a ratio of the positional change in a period for normal velocity, but we utilise angle instead of distance here. Definition of angular velocity using linear velocity The second angular velocity formula, v = r, may be obtained from the linear velocity and radius relationship using the cross product.
_______________________________________________________
(Hope this helps can I pls have brainlist (crown)☺️)
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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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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which color of light, red or blue, travels faster in crown glass?
Answer:
Red
Explanation:
The index of refraction for red light in crown glass is smaller than the index of refraction for blue light, which means the speed of red light is larger than the speed of blue light in crown glass.
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 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