Answer:
Electric field at a point ( x , y , z) is
.
Explanation:
Given :
Electric potential in the region is , 
We need to find the electric field .
We know , electric field ,
{ Here r is distance }
In coordinate system ,
{
is partial derivative }
Putting all values we get ,

Hence , this is the required solution.
Answer:
Part a)

Part b)

Part c)
Since we know that the base area will remain same always
so here the length and width of the object is not necessary to obtain the above data in such type of questions
Explanation:
Part a)
As we know that when cylinder float in the water then weight of the cylinder is counter balanced by the buoyancy force
So here we know
buoyancy force is given as



Now we know that the weight of the cylinder is given as

now we have


Part b)
When the same cylinder is floating in other liquid then we will have

so we have


Part c)
Since we know that the base area will remain same always
so here the length and width of the object is not necessary to obtain the above data in such type of questions
Answer:
70.15 Joule
Explanation:
mass of man, m = 70 kg
intial length, l = 11 m
extension, Δl = 1.5 m
Let K is the spring constant.
In the equilibrium position
mg = K l
70 x 9.8 = K x 11
K = 62.36 N/m
Potential energy stored, U = 0.5 x K x Δl²
U = 0.5 x 62.36 x 1.5 x 1.5
U = 70.15 Joule
Phase 1. Forethought/preaction—This phase precedes the actual performance; sets the stage for action; maps out the tasks to minimize the unknown; and helps to develop a positive mindset. Realistic expectations can make the task more appealing. Goals must be set as specific outcomes, arranged in order from short-term to long-term. We have to ask students to consider the following:
<span>When will they start?Where will they do the work?How will they get started?<span>What conditions will help or hinder their learning activities are a part of this phase?
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Phase 2. Performance control—This phase involves processes during learning and the active attempt to utilize specific strategies to help a student become more successful.
We have to ask students to consider the following:
<span>Are students accomplishing what they hoped to do?Are they being distracted?Is this taking more time than they thought?Under what conditions do they accomplish the most?What questions can they ask themselves while they are working?<span>How can they encourage themselves to keep working (including self-talk—come on, get your work done so you can watch that television show or read your magazine!)
</span></span>
Phase 3. Self-reflection—This phase involves reflection after the performance, a self-evaluation of outcomes compared to goals.
We have to ask students to consider the following:
<span>Did they accomplish what they planned to do?Were they distracted and how did they get back to work?Did they plan enough time or did they need more time than they thought?<span>Under what conditions did they accomplish the most work.
Hope this helps!!!!!
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Answer: f = 927.55Hz
Explanation: Since the the tube is open-closed, the length of air and the wavelength of sound passing through the tube is given below
L = λ/4 where λ = wavelength.
speed of sound in air = v = 343m/s.
fundamental frequency of open closed tube = 315Hz
λ = 4L.
v = fλ
343 = 315 * 4L
343 = 1260 * L
L = 343/ 1260
L = 0.27m
In the same tube of length L = 0.27m but different medium ( helium), the speed of sound is 1010m/s.
The length of tube and wavelength are related by the formulae below
L = λ/4, λ=4L
λ = 4 * 0.27
λ = 1.087m.
v = fλ
1010 = f * 1.087
f = 1010/1.807
f = 927.55Hz