Homework Statement
A 5.0kg block initally traveling at 11m/s moves up a 30degrees incline. A frictional force of 9.4N acts on the block as it moves up the incline. What maximum vertical height, h, will the block reach?
m = 5.0kg, vi = 11m/s, vf = 0m/s, Fr = 9.4N,
Homework Equations...
Why is the Maximum Likelihood function a product?
Explanations of how the Maximum Likelihood function is constructed usually just mention that events are independent and so the probability of several such events is just the product of the separate probabilities. I get the logic w.r.t...
Here's the situation:
A small block of wood of inertia mb is released from rest a distance h above the ground, directly above your head. You decide to shoot it with your pellet gun, which fires a pellet of inertia mp. After the block has fallen a distance d, the pellet hits it and becomes...
Homework Statement
The maximum torque on a lever is 1.5 x 10^6 Newtons. How many people of weight 750N can stand evenly spaced on this lever, which has a length of 20 meters?
Homework Equations
T=FR
Weight=mg
W=Fd
X = Number of people
The Attempt at a Solution
I have set 1.5x10^6 N =...
Homework Statement
A tube containing a isotope of radon, 22286Rn, is to be implanted in a patient. The radon has an initial activity of 1.6 * 104 Bq, a half-life of 4 days and it decays by alpha emission. To provide the correct dose, the tube, containing a freshly prepared sample of the...
Hello, I have to find the density of probability which gives the maximum of the entropy with the following constraint\bar{x} = \int x\rho(x)dx
\int \rho(x) dx = 1
the entropy is : S = -\int \rho(x) ln(\rho(x)) dx
L = -\int \rho(x) ln(\rho(x)) dx - \lambda_1 ( \int \rho(x) dx -1 ) -...
This question comes from the equation E = vB (moving conductor in a magnetic field -- E = electric intensity, v= speed of the conductor's movement, and B = magnetic field strength). Say B is constant, so the only thing we have to rely on to vary the electric intensity in the conductor is its...
Homework Statement
As shown in the figure below, beams of light whose wavelength in air is 600 nm are perpendicularly incident upon two transparent thin films (A and B) in the same phase. The thickness of A and B is l. The refractive indices of A and B are, respectively, nA and nB. The...
Homework Statement
A 28-kg rock approaches the foot of a hill with a speed of 15 m/s. This hill slopes upward at a constant angle of 40.0∘ above the horizontal. The coefficients of static and kinetic friction between the hill and the rock are 0.75 and 0.20, respectively.
a)Use energy...
The problem reads: "You are given a string of fixed length l with one end fastened at the origin O, and you are to place the string in the (x, y) plane with its other end on the x-axis in such a way as to maximise the area between the string and the x axis. Show that the required shape is a...
I remember doing a physics problem over 30 years ago but I can't remember enough to do it again. The only reason I remember it is that it seemed like it would be so useful when I had teenage kids. Funny how the brain works sometimes. Got teenagers now. We were working on acoustics. If I...
Question :-
A car has to move on a path, that is a arc of a circle of radius (##R##). The length of the path is (##L##). Suppose it starts on the highest point of the path, find the highest uniform speed for which, it does not lose contact with the path on any point ?
My attempt :-
I made a...
Suppose ##\intop_{-\infty}^{+\infty}(f(x))^{2}dx=1##, and ##a=\intop_{-\infty}^{+\infty}(\frac{df(x)}{dx})^{2}dx##, does a maximum value of ##a## exist? If it exists, what's the corresponding ##f(x)##?
Homework Statement
Using the maximum power transfer theorem, find the value of R which will result in the maximum power being delivered to R.
Homework Equations
P_max= (V_oc)^2/4(R_th))
R_L=R_th
P_RL=(V_th/(R_th+R_L))^2*R_L
The Attempt at a Solution
I have no clue where to even begin with...
Hello Physics Forums,
I've been looking around on these forums for help with trying to calculate the max velocity of an electric longboard my group of friends are making. After reading a few posts, you guys have helped me understand these calculation a lot better.
Right now we have a gear we...
I started simply looking at a circuit breaker connection diagram, then I fell down the rabbit hole.
So I wondered, if you had a piece of pure copper and getting rid of heat (structural integrity, gravity etc.) was not an issue, just how much current could you push through it before it hit it's...
I'm wondering about theoretical maximum velocities of supersonic electric aircraft. I think the fastest demonstration of any type of aircraft has been close to mach 10. This was done using a rocket engine, so propulsion would not be limited by air characteristics as much as a fan's propulsion...
Homework Statement
Show that the largest possible change in the kinetic energy , ##\Delta E_{kin}##, of a particle of mass ##m## running into another particle of mass ##M## at rest in the lab coordinate system is
\Delta E_{kin} = \frac{-4AE_{kin}}{(1+A)^{2}}, where ##A = \frac{M}{m}##...
Homework Statement
Find the maximum compression in the spring, if the lower block is shifted to rightwards with acceleration of '##a##'. All the surfaces are smooth.
Homework Equations
$$\vec{F}=m\vec{a}$$
$$\vec{F}_{sp}=k\vec{x}$$
The Attempt at a Solution
FBD of the upper block:
From...
Homework Statement
A spring of negligible mass has force constant k = 1800 N/m .
You place the spring vertically with one end on the floor. You then lay a 1.30-kg book on top of the spring and release the book from rest. Find the maximum distance the spring will be compressed.
Homework...
According to Coulomb's law, the electric force between two, equal in magnitude and opposite in direction, charges depends on the distance between them, and as they get close to each other, the force increases and the distance decreases. At the position when they get stuck with each other, the...
Hey all,
I'm a bit of a food geek and a DIY nut and I'm looking to build my own vacuum sealer for as cheap as possible. My question to you guys, is what is the cheapest material I can use that will still withstand the pressure as well as maintain the airtight seal needed? I am looking to get a...
A common student misconception is that when a ball is thrown straight up in the air, at the point of maximum height, where the velocity is zero, the acceleration is also zero. This can easily be dispelled by observing that, if indeed the acceleration were zero when the velocity is zero, the...
Homework Statement
Calculating the moment of force F about the axis isn't hard; how do I determine how to produce the maximum moment?
Homework Equations
Maxis = ûaxis ⋅ (r×F)
F = 30N (This doesn't change at all during the problem)
The Attempt at a Solution
I would guess that since the...
Mass of a book of type X = 40g;
Mass of a book of type Y=80g;
The total mass of n books of type X and one book of type Y is less than 200g;
i. Write down an inequality containing the variable n only.
ii. Solve the above inequality for n and write down the maximum possible value for n
So how...
Determine the maximum ratio $$h/b$$ for which the homogenous block will slide without toppling under the action of force F.The coefficient of static friction between the block and the incline is $$\mu_s$$.
I have a doubt.About which point should the rotational equilibrium be applied?Should it...
Homework Statement
A uniform bar with length c can slide a cylindrical surface with a radius of r. Determine the maximum angle theta that guarantees the equilibrium of the bar if the friction coefficient at the points of contact is u.
Homework Equations
Friction force = u*N (where N is the...
Homework Statement
The instantaneous speed of a particle moving along one straight line is v(t) = ate-3t, where the speed v is measured in meters per second, the time t is measured in seconds, and the magnitude of the constant a is measured in meters per second squared. What is its maximum...
Homework Statement
We have a concrete mixer, and if the drum spins too fast, the ingredients will stick to the wall of the drum rather than mix. Assume that the drum of the mixer has radius R = 0.5 m and that it is mounted with its axle horizontal. What is the fastest the drum can rotate...
Hi,
I was thinking if maximum light intensity underwater during seasons changes somehow.
I firstly thought about considering monthly solar irradiance (http://neo.sci.gsfc.nasa.gov/view.php?datasetId=CERES_INSOL_M) however I thought this would have been biased at certain latitudes due to...
Hi all
Tearing my hair out trying to calculate the Maximum acceptance angle for a problem. Experiment involved shining a laser into a tube of water. I have calculated the angle of refraction based on the average of two critical angles (one known and one measured manually) as 52.49 degrees...
Hi there!
I have a basic question here, hopefully someone can brush physics up for me.
I have a motor that is capable of max velocity of 5000°/s, and max acceleration of 30000°/s².
What is the minimum distance that the motor need to travel before it reaches that max velocity?
Can it make it in...
it is given that the perimeter of the rectangle is (80 + 120 + 80 + 120) = 400 cm From this you need to make a cylinder with maximin volume:
400 = 2r + 2h
2h = 400 - 2r
h = 200 - r .
We wish to MAXIMIZE the total VOLUME of the resulting CYLINDER
V = πr^2 h
However, before we differentiate the...
Homework Statement
Adjacent antinodes of a standing wave on a string are 15.0cm apart. A particle at an antinode oscillates in simple harmonic motion with amplitude 0.850cm and period 0.0750s. The string lies along the +x-axis and is fixed at x = 0.
the speed of the two traveling waves are...
Homework Statement
Two speakers are arranged as shown. For this problem, assume that point O is 12 m along the center line and the speakers are separated by a distance of 1.5 m. As the listener moves toward point P from point O, a series of alternating minima and maxima is encountered. The...
Homework Statement
Cylinder A (mass = 5kg) is released from rest at a height h =100mm above a spring of stiffness k = 1.8 kN/m. Determine, (i) the maximum compression of the spring, (ii) the spring deflection when the cylinder’s velocity is a maximum, and, (iii) the maximum velocity of the...
Homework Statement
why the maximum bending moment at the center is w(l^2) /8 ?
Homework EquationsThe Attempt at a Solution
shouldn't it be = 0 ?
when we take the moment about the center , the reaction force at the left will generate clockwise moment , while the reaction force at the right...
Homework Statement
A sinusoidal wave on a rope with linear density ##\mu=0.012 kg/m## is described in SI units by $$\xi(x,t)=A sin (kx-\omega t)= 0.15sin(0.8x-50t)$$
a) find the maximum acceleration of a rope element
b) find the maximum transverse force on a piece of rope ##1 cm## long
c) Show...
Homework Statement
how the author found the maximum moment = 0.29MNm ? is there any formula ? how to find it in this question ?
Homework EquationsThe Attempt at a Solution
Few days ago I got sample of toroidal core from my friend. Technical details of core OD-10cm, ID-6cm, height- 5cm and wet about 1.845 kg(M4 grade CRGO). I want to make toroidal transformer using this core but how to calculate core area and maximum VA capacity of core. attach Test certificate of...
I have a particle that travels in the cartesian plane with the maximum velocity of A units along the x-axis and B units along the y-axis per unit of time.
How do I go about deriving the maximum velocity of my particle in the rotated uv plane? (the maximum distance the particle can along the u...
Purchased a Netgear R7000 Nighthawk router that has 3 antennas mounted on the back. Is the maximum signal strength in the direction formed by the plane of the 3 antennas (left to right) or perpendicular to that plane (front to back)?
Homework Statement
A light ray falls from the air (##n_a=1##) into the center of the upper surface of a long cilindrical glass tube with an index of refraction ##n_t=3/2##. The tube is submerged into water all the way to the upper edge and the waters index of refraction is ##n_w=4/3##. What is...
Hi there...
I have an application where I know the vibration frequency/force/acceleration of the source...
How can I find the maximum theoretical power output (in mw/watts...) of a tuned piezo where its resonance is the same as the source vibration frequency...
Hi,
I have this question.
An instrumentation measuring system uses a differential amplifier having a CMRR of 120 dB and differential gain of 105. The maximum differential input signal is 60 μV. If the amplified noise voltage is specified to be not more than 1% of the maximum output voltage...
Is latex balloon maximum strain independent of latex thickness?
I have been in search of a latex balloon that is relatively small when deflated and very large when fully inflated. Standard balloons that reach the desired inflated dimensions are much larger deflated than I would like...
Homework Statement
A person stands in an open space listening to the sound from two speakers. The speakers generate sound with a frequency of 489.5 Hz, the speed of sound in air is 343 m/s. The speakers are 2.00 m apart and the person walks away from one of the speakers along a line that is...
Hello,in this link http://dtic.mil/dtic/tr/fulltext/u2/a028054.pdf a paper „Maximum Theoretical Angular Accuracy of Planer and Linear Arrays of Sensors“ can be found.The accuracies are given in equations 19 (respect to the x axis) and 20 (respect to the y axis).My question is: Shall the angle...
Homework Statement
The longest homerun hit by Miguel Cabrera in the 2012 season occurred at Comerica Park and had an initial y-component of velocity of 19.8 m/s and an initial x-component of velocity given as m/s, where is some value left undetermined.
Assume the ball left the bat 1.22 m off...