A block of the periodic table is a set of elements unified by the orbitals their valence electrons or vacancies lie in. The term appears to have been first used by Charles Janet. Each block is named after its characteristic orbital: s-block, p-block, d-block, and f-block.
The block names (s, p, d, and f) are derived from the spectroscopic notation for the value of an electron's azimuthal quantum number: sharp (0), principal (1), diffuse (2), or fundamental (3). Succeeding notations proceed in alphabetical order, as g, h, etc.
Refreshing on this...This is a relatively new area to me ...my solutions should be correct...what i am trying to engage on is if there are any other ways of looking at the same problem.
Ok in my working i have,
##30 + 35 \cos β-45=0##
##\cos β=0.4286##
##β = 64.62^0, ⇒θ=25.4^0 ## to one...
Pretty straight forward, ...reason of posting is to check why i am having a negative value for ##a##.
From my study, i know that
##R(||)## to plane
##F - 40 \cos \dfrac{π}{3} = 4a##
##a = -5 m/s^2##
or can i as well have the equation ( friction and tension are at equilibrium) as,
##40...
I just want to know how strong I have to be to move a large stone block by tumbling it over.
A formula is what I'm looking for I guess.
Assume a perfect cube.
Begin with a raised edge making say 10 degree angle with the ground.
I get my fingers in there and start lifting.
I suppose when I get to...
The first equation is when I use forces. The block is in static equilibrium, therefore the spring force should balance the gravitational force.
The second equation is when I use energy principles. Energy before compression = Energy at compression. The height before is x * sintheta, and the...
a) For the model, I'm not sure how to include all the forces I think are present. Gravity, normal force from the ice, contact force from ice to person, and person to ice. Is there also a normal force keeping the person's hands from going "into" the ice?
b) As for part b, I would think to use...
I use Norton protection. They offer VPN. I try to use it. But I was blocked by a site after I use the VPN. I had to turn VPN off to get to the site.
Why? and what can I do to resolve this and still use VPN?
Thanks
Energy lost by water = Energy gained by ice
Energy lost by water = 0.16 x 4200 x (100-t)
Energy gained by ice = 0.205 x L + 0.205 x (t) (where t is the temperature at thermal equilibrium). However, there does not appear to be enough info to continue.
The solution, however, considered t to be...
This was the question:
I derived the equations as mentioned in the relevant equations.
But I could not solve the equations to find the answer. I realise with respect to inclined plane the acceleration must be a since string cannot slack. With respect to ground, the acceleration of incline is...
FIGURE 5 shows an electrically heated oven and its associated control
circuitry. The current, I, to the oven's heating element is fed from a
voltage-controlled power amplifier such that I = EK1. A voltage, VD, derived
from a potentiometer, sets the desired oven temperature, TD. The oven...
If I say run the httr library on R and send DELETE or PUT or POST requests to a website, can it alter the contents and display of the webpage or do we devs have methods to block requests from unidentified sources. E.g if I send a DELETE request to Physics Forums website does it mean I can take...
Sets are called the building block of maths, but why? To me sets are a collection of 'things'. Were as numbers are what give the 'things' a meaning. Myself I think that addition is the building block and maybe subtraction, all the other processes, addition and division are only quick ways of...
$$ \frac{5E-3*v^2}{2} = (2 + 5E-3)(10)(0.2)(2) $$
v = 56.64
I just don't get how this is the wrong answer....it's just simple conservation of energy, right?
Since this is a "general lounge" area, I will assume this rather personal story is not out of line. I am 64 years old (relevance of my age should become clear shortly) and graduated from an Ivy League University in 1980 with a degree in Electrical Engineering. I also scored over 700 on my math...
We want to figure out how much work friction does on a block as it slides down an inclined plane with a rough surface.
we find the force due to gravity that pulls the block down the ramp, that's found by M * g * sin(θ),
The normal force on the block is given by M * g * cos(θ).
The force of...
So here's what I did but it isn't right:
W = (Kf + Uf) - (Ki + Ui)
(2.6)(9.81)(0.45)(-0.01)=(1/2mvf^2 + 1/2kxf^2) - (1/2mvi^2 + 1/2kxi^2)
-0.1 = (1/2(2.6)(vf^2) + 1/2(855)(0.02^2)) - (1/2(855)(0.03^2))
1.3Vf^2 = 0.114
Vf^2 = 0.09
Vf = 0.3 m/s
Picture of problem:
For the object to be moving, it must overcome friction.
##f=0.5*0.6F = 0.3F##
##mg=22N##
Upward motion:
##0.8F>mg+f \rightarrow 0.5F>22 \rightarrow F>44N ##
Downward motion:
##0.8F+f<mg \rightarrow 1.1F<22 \rightarrow F<20N ##
I think correct option is D. Can you please...
The block starts to slide if friction can no longer hold the block.
F=u*n and F=(m1+m2)a
so: (m1+m2)a=uN=>am1+am2=uN=>am2=(uN)/(am1)
So:am2=(uN)/(am1) is the force.
The answer is F=(u*m1g(m1+m2))/m2
I do not see how the acceleration terms are canceled. Is my answer equivalent to this?
I was able to solve for a, b, c, and d.
I don't know whether I'm saying it right for part e.
The first scenario is a perfectly inelastic collision. After impact, the bullet transfers momentum to the block, causing the block to move (it was initially at rest), and the bullet + block fall at a...
Hi all so I had a injector go on my audi q5 2009 and had a mechanic to put a new injector in it and a Alternator and auxiliary belt so after the work be done I take it for a drive did about 2miles than Start it to make Allowed tapping noise so get hold of mechanic and he's said get it home than...
So far I have reached a pretty promising equation that if uk * g >= F/(m1+m2+…+mn) then kth block will atleast surely not slide wrt the lower one. But the converse to this that if uk * g < … then it will “surely” slide is wrong!!
Stuck on this from many days!
Thanks (:
My attempt:
As I need to find acceleration I believe that I need to use F=ma(and thus draw a free body diagram).
I drew the block's weight components(mgsinθ, mgcosθ) and concluded that the only force acting on the plane in the horizontal direction is the horizontal component of...
Note: wording is ambiguous so I assumed spring started from equilibrium, in which case it stretches as we go downslope. Final height (at lower point on slope) is 0.
Distance along slope = Distance the spring stretches = d= ##s_f## = ##2/cos{\theta}## =2.13
Height change = h = ##2 tan{\theta}##...
The contact force on 10 kg due to 20 kg is taken as Fc2
m1 = 30kg, m2 = 20kg, m3 = 10kg
F_A = Applied force
μ = 0.15
Net force = mass X acceleration
Fc2-Friction force = m3 X a, where a = F_A / (m1 +m2+ m3). Therefore the equation becomes
Fc2 = m3 F_A/(m1+m2+m3) + μN
= F_A/6 +15
I...
What I think I should do:
1 = 0001
7 = 0111
3 = 0011
First block = 00010111
Second Block = 00110000
Now, I do binary division
00010111/11010 = find the answer
00110000/11010 = find the answer
This is what I think I should do, but I am not sure if this is correct. Is this basically CRC?
Any...
For the second force with the spring, I know the spring force will exert a force back on my hand, for example, but I'm confused whether the applied force is transmitted unchanged to the block or whether it will decrease because of the opposite spring force. What happens to the block when the...
I don't understand the question. If it want the mass to stop and reverse its direction, then does that not means ##vo## can be anything? (obviously not 0 since it will make the system not moving at all).
I have no idea how to start this other than that I think that Fn is 17.64N and Fnet is 0. But I don't have the mew, so I am not sure how I am going to get the force of static friction.
If I shoot a block with mass m1 with initial velocity v, and the block m1 goes to the end of the string tethered to the bottom block with m2 without lifting it up, what is the force equation involved with the block with m1?
I am torn between whether it would be
1) -T -m1*g = 0, which I am...
We have the string's mass constraint m(x) = m(x/L). The block is accelerated right by force T(x=0) = Ma, where a = F / m + M.
But at the point where the force is applied (i.e. x = L), I believe we have m(L/L)a = ma = F - T(L). But this would imply T(L) = F - ma = F - m(F / m + M) = F(M / m + M)...
My solution for part b) (i.e. minimum acceleration) in case it's needed: https://ibb.co/D8CCQMM
I'm confused about part c.
1) Since the block will travel up the incline if a > a_max, acos(theta) is up the incline. But based on my attached FBD diagram, acos(theta) should be down the incline...
Hi so with this question, I am really confused. Even from the start. Like it doesn't tell us where the force is acting on. From top of block, middle of block etc? And I know how to determine the direction of moment for something on a pivot, not in this scenario though. The answer is A. They did...
I have drawn a fbd and the logic I think is that at rest the block moves down the wedge but when a force P is applied vertical force becomes zero and the horizontal force ##F_N\sin \beta## = P?
The best I could do was draw a forces diagram. I know that friction would be working up when the block is on the point of slipping down the plane and friction will be acting down the slope against the direction of motion when the block is on the point of slipping up the slope. (not even sure if...
hey i would like to understand something, i solve this question but i don't understand why my answer is right, first of all we learn that in problems like this we need to disassemble into components the mg and that what i try to do here but i didnt get the right answer so then i try to do same...
I can understand that using conservation of momentum, we can find v. But we need V for that. The equation for V involves h and so we need h. But I am not able to comprehend the equation involving l,h and a. The question doesn't specify what a is.
Please be kind to help
My doubts are as follows-:
-> Why frame n is not segmented to blocks?
-> Why no inputs from (n-1) side for block matching?
-> What do we do in prediction error coding?
Source-: https://homepages.inf.ed.ac.uk/rbf/CVonline/LOCAL_COPIES/AV0506/s0561282.pdf
I have read this many times but that...
https://lh4.googleusercontent.com/g6wQjnQ6p3IVt86-_kwnNVwyOb_iUxUXWChyf0XZR5PO17uOnPbNhCxdpfUSScvU8sAR8Al2FNRMoeMEqLUUuJsvGOSnpFO94tutB2h-927rxVYRDUGzi-JF9FYs9hKivGdCvrAP
My doubts are as follows-:
-> Why frame n is not segmented to blocks?
-> Why no inputs from (n-1) side for block matching...
At the time of release, the equation of motion of blocks A and B T-m_ag = m_aa and T=m_b\omega^2R respectively, where T is the tension in the string. Solving for the acceleration a then gives a=\frac{m_b\omega^2R - m_ag}{m_a}. Not sure what I did wrong or what incorrect assumptions I made...
hey I am really hope for some help becuase i don't know what I am doing wrong, the angle of the first part is 21.801.
here is my solution i would like to know what I am doing wrong
Summary:: What is the sliding resistance of an eccentrically loaded block on a flat surface?
If a 1000kg block is placed on a flat surface (say coeff. of friction = 0.4), what force does it take to slide if it loaded eccentrically, i.e. at the far edge of the block?
My thinking is there is...
##W_{ext}=mgh+KE_f+0=-20(5\sin 37)+(1/2)2(10^2)##
##W_{ext}=-60.18+100=39.81J##
But it’s not consistent with ##W=F.d=20*5=100J##
I can’t figure it out.
EDIT for clarity: I solved the question, just asking for if the explanations make sense and if the mechanical energy is considered to be conserved before and after the collision due to reasons listed below the photo.
I hope this image is readable (grr, scanner is janky).
I'm guessing the...