A backpack is attached to a spring scale which is attached to the ceiling of an elevator. The elevator is moving downwards with an acceleration of 3.8 m/s^2. The scale reads 60 N (Fscale). What is the mass of the backpack?
The solution to this problem says that Fscale - w (weight) = Fnet.
This...
The problem that i am facing has to do with acceleration. The problem states that we have two balls with the same mass m that stands on two different tables. Between these balls are a wire with the length 2l, which i assume means 2 * l, where l is a value i choose. In the middle of the wire (x =...
https://www.feynmanlectures.caltech.edu/I_09.html
“Weight and inertia are proportional, and on the earth’s surface are often taken to be numerically equal, which causes a certain confusion to the student. On Mars, weights would be different but the amount of force needed to overcome inertia...
For lower half ,$$Fnet=-\mu F_N+mg\sin \phi$$
For upper half,
$$v^2=u^2+2as$$ (s is half of the total slant distance)
$$v^2=0+2\frac{mg\sin \phi}ms$$
$$v=\sqrt{2g\sin \phi s}$$
again for lower half,
$$v^2=u^2+2as$$
$$0=2g\sin \phi s+2\frac{-\mu F_N+mg\sin \phi}ms$$
$$\mu=\frac{2gm\sin...
I looked for solutions on the internet but all of them had given mass and looked for volume , but that isn't given here.
I tried something like subtracting the two weights or trying to find mass from the weight but i can't find the correct awnser
Hello,
I am teaching eleven year olds about gravity. There is no issue about this subject, however I would like someone to help with a model answer.
As mass never changes. What is the best answer when I am asked that if someone gets 'fatter', do they not put on mass?
Thanks in advance.
Is the pole mass of the particle it's characteristic mass? When particle physicists calculate the mass of elementary particles, like top quark, do they mean the pole mass? If not what makes the apparent mass of a particle different from pole mass?
During beta decay an electron and neutrino are emitted at very high speeds. I thought that the electron and neutrino were the product of w boson decay but I recently learned w bosons are over 80 GeV worth of energy. My question is, where does this mass come from? I know that atoms get enough...
Hi guys,
M can then be split up into 2 components: the mass of the payload which is known, and the mass of the wing.
The wing material has a known thickness and density meaning its mass is given by: surface area of wing* mass per m^2 (mass m^2 is used as density and thickness are known so an...
Hello,
I've worked through the free-body diagram to compute the answer:
tan(𝜃) = 0.67
𝜃 = arctan(0.67) = 33.822...
The answer is supposed to be approximately 42. Yet, tan(42) is not 0.67, is the suggested answer wrong?
My high school physics days are long ago ;) This is not homework, well, other than it is work, at home.
For a real application: Very space constrained "workshop", got a bench drill press, and want to build a table on wheels for it, to be able to move it into a corner when not needed.
Those...
I recently encountered this problem on a test where the solution for the above problem was given as follows:
$$F= \frac{Gm_1m_2} {r^2} $$ (1)
but
$$ m=\frac{4}{3}\pi R^3 $$
substituting in equation (1)
$$F= \frac{{G(\frac{4}{3}\pi R^3\rho})^2 }{2R^2} $$
where r=radii of the two spheres
m=mass...
I'm surprised that this question only occurred to me recently. If a have an electrically charged mass attached to a spring and set it oscillating, the resulting production of electromagnetic waves must cause a kind of "friction", a force resisting the motion of the charged mass, so that its...
So there is a post going around the facebook groups about what would happen if we could pour a Sun sized bucket of water onto the sun, the claim being that the sun would gain mass and become a bigger, hotter burning blue star. I know this cannot happen but I was just curious as to what would...
a) Two particles have energies E1 and E2, and momenta p1 and p2. Write down an expression for the invariant mass of this two-particle system. Leave your answer in terms of E1 and E2, and p1 and p2.
b) A typical photon (γ) in the Cosmic Microwave Background (CMB) has an energy of kBTCMB, where...
Hi,
The solution for this question is
thermal energy lost= thermal energy gained
0.200x450x(300-T)=1.0x4200x(T-20)
T=26 degrees celcius.
However, I am struggling to grasp why (300-T) is used.
I have always known a change in something to be final - initial. Therefore change in T= Final-...
Good Evening All,
I have an assignment i am struggling with really hope you can help.
The question reads Describe how force, momentum, Angular momentum, kinetic and potential energy are linked with respect to mass, acceleration and velocity
I know the following
Force – the push or pull...
Please some one help! I am about to go stir crazy. I am really struggling to answer a the following question...describe how force, momentum, Angular momentum, kinetic and potential energy are linked with respect to mass, acceleration and velocity.
Its probably really easy but science is not my...
Lets take the original position of the man to be our origin
The plank is uniform so we can assume its mass to be concentrated at its center i.e. 4m from the origin
Xcom= m1x1+m2x2/m1+m2
=50(0) +150(4) /50+150
=3m
There is no external force on the system so the centre of mass does not move...
I saw the following problem in a test I was reviewing:
I don't understand how they got their answer. I used the formula: ƒ=sqrt(T / u) / 2L where f is the frequency of the string, T is the tension, u is the linear mass density, and L is the length of the string.
I got:
T = mg = 50 * 9.8 = 490N...
I am not really sure what to do to find the mass of satellite.
Equation for orbital speed:
$$m \frac{v^2}{r}=G\frac{m_1 . m_2}{r^2}$$
$$v_{orbital}=\sqrt{\frac{GM}{r}}$$
Equation for escape speed:
$$KE_1+GPE_1=KE_2+GPE_2$$
I tried to take position 1 as the position where the satellite orbits...
Using Lane Emden and n = 3 (relativistic), I calculate the correct mass -- the Chandrasekhar mass (about 1.4 Msun)
The equation goes Mtotal ∝ a3, because at n=3, the density, ρ, cancels out.
a2 ∝ K/G = Kg2 → a3 ∝ Kg3. Here K ∝ h c or Kg m3/sec2 and G ∝ m3/Kg/sec2
This implies the mass, Mtotal...
Hi, I am trying to determine the velocity of the particle with the mass m coming out of the acclerator.
I tried writing :
Ep(i) + Ec(i) = Ep(f) + Ec(f)
Ec(f) = Ec(i) - Ec(f)
But at this step, I'm no longer sure how to express Ep with V because :
In my textbook, it's written :
Ep = 0,5...
Hi all,
This may be simple chemistry, but I haven’t engaged this topic for a very long time.
I have an experiment where I need to measure the masses of some elemental (99%pure) metal cubes and I also want to know how many atoms of each element there are within them.
From memory, Avogadro’s...
It's a well known fact that acceleration due to gravity is independent of the mass of the accelerating body, and only depends on the mass of the body it is accelerating towards and the distance from it.
One can prove this mathematically very easily.
F=GMm/r^2 (equation 1)
but also F=ma...
I averaged the masses and times (which i took the time given and divided by 10 because in the problem it says you measure the time it takes to complete 10 oscillations) then plugged them directly into the T=(2(pi)((m/k)^1/2) and got the wrong answer. This is really confusing me because I don't...
Hi There,
I am wanting to calculate the amount of deflection (δ) from a simply supported Beam. My Beam is an Aluminium Tube ø30mm with a 3mm Wall Thickness.
Force (F) - 500N
Length (L) - 610mm
Youngs Modulus (E) - 68 Gpa
Moment of Inertia (I) - ?
δ = F L³ ∕ 48 E I
Q1: Is this the correct...
I am trying to find the mass flow rate of coolant through a channel within a hexagonal nuclear fuel assembly. I am given the specific heat of the fluid, the coolant inlet and outlet temperatures, the total power produced by a single fuel pin, the diameter of the fuel pin, the length of the fuel...
Denote wheel turning angle as theta--> Induced EFM (Em)=Kb*Theta_dot.
Voltages on the wheel: R*i= V - Em
Moments on engine's axis: Kt*i-C*a + a (m+M)*x_double_dot=0 (As Jm negligible).
From here I would find another equation to have x and theta expressing each other, but i think I'm...
I had solved this question but it didn't seem to be appropriate to post in the classical physics problem as my question is still homework-based.
Originally I had thought this might be a conservation of momentum problem. But since we don't have any initial conditions it leaves too much to guess...
Summary:: Not looking for concrete answers, just want to spitball some ideas about the basics of Algae cultivation and implications of scaling to large scale.
So the idea is this:
Build massive ponds and seed them with an initial culture of algae.
Wait one doubling period and filter out half...
What I did first is to find the tension T1 and T2;
T1=(mg)/[sin(55)]
T1=(40N)/[sin(55)]
T1=48.83N
T2=T1cos(55)
T2=(48.83N)[cos(55)]
T2=28.01N
Now I do not know how to proceed. Can someone help me?
I wrote a program to determine the critical mass of uranium oxide with an enrichment of 10%. I got a keff approximately equal to 1 with the selected volume and density (attached a file). Is it possible to somehow run the program without writing the initial density and volume into the conditions...
I am not sure what form of mass conservation to use to solve the above problem from An Introduction to Combustion by Stephen Turns. Can anyone explain what form of mass conservation applies to a sphere in this context?
There is a number floating around on the internet that says that the mass of the Earth's atmosphere is about 5 quintillion kilograms. The way that that number was calculated was through knowing that per square meter of surface area at sea level, about 100,000 Newtons of force is applied, which...
I haven't gotten anywhere. I don't find it possible to calculate this since Fg varies based on the Mass of the meteroide and because of that it will change acceleration. I thought about trying to remove m1 by making F=m*a the same as 𝜸(m1*m2)/r^2 since I think they are the same force.
m*a=...
I thought that the force by the pivot A on the pole AB would be the reaction force to the x-component of the gravitational force on AB. This would mean that the force by the pivot would be parallel to the pole, but in my notes from class the force vector seems to be more along the bisector of...
I read this -
https://www.sciencedaily.com/releases/2018/01/180116093650.htm
And I see this -
"However, there are indications that a neutron star with a maximum mass would collapse to a black hole if even just a single neutron were added."
And I think the maximum mass of a neutron star is...