# Questions tagged [homework]

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### How to calculate internal convection loss in a sealed container?

Say I have a box with a 1m x 1m x 1m interior wall dimension. The side walls and the floor are 10cm of styrofoam, with a thermal conductivity of 0.03 W/m K. The top is 1cm thick opaque plastic with ...
117 views

### Calculating two diagonal forces

When I tried to calculate the force exerted on the rope 'a' I get that it is equal to 5N when the block has a force of 10N. Do I instead need to divide by 30 since the sum of the two angles is 30 ...
17 views

### How do I derive the expression of boundary work in relation to a polytropic index?

I don't understand how to derive the formula, How do I derive the expression of boundary work in relation to a polytropic index? I used the Definition of boundary work for a polytropic index, the ...
16 views

### Energy conservation on SHM in springs

In the above spring block arrangements, the time period is asked for $K_1=2K$ left spring and $K_2=K$ right spring. Now at equilibrium, $$T=K_2x=Kx=mg$$ $$2T=K_1y=2Ky=2mg \implies x=y$$ for movable ...
19 views

### Hydrographic Survey Problem

I have been trying, but I can't figure out how I should solve this using the area velocity method. It is the only method as our professor taught us. Any help would be appreciated.
43 views

### Cooling steel by putting it in water ; what is the final temperature

Below is a problem I made up and did. I am hoping that you will tell me that my solution is right. Problem: A $5$g piece of steel at $30$°C is placed in $400$ ml of water at $20$°C. Assume that all ...
34 views

### How do I draw a circuit for a conducting loop inside a solenoid?

To solve a homework problem, I need to redraw the following diagram in circuit form. The large blue circle represents the solenoid. Inside the solenoid, the two gray semicircles represent a wire loop,...
56 views

### How to draw a isometric view of the block in the picture below?

Can anyone give me some guidance with this question? I'm finding it a bit difficult.How is the object suppose to look like?
1 vote
43 views

### Impact of decreasing weight from a part of body w.r.t tipping

If I decrease the weight from top portion of the body keeping all dimensions same, the center of mass shifts downwards, but does it makes it more stable against tipping from perpendicular forces ? ...
1 vote
262 views

### What are the conditions for a signal to be an energy signal and a power signal?

I know how to find the power and the energy of a signal. What I have a problem with is knowing whether a signal is an energy signal or a power signal. According to my teacher, a signal is a power ...
2k views

### Calculating Entropy from Gibbs Free Energy?

I guess Cp = dH/dT= dq/dT=dS Thus SdT = integral of CpdT. From that ∆H is given and we can calculate ∆G. However, entropy for this reaction should be -7.4J/molK and I am getting like 26J/molK. Also S ...
106 views

### I am struggling to get the right answer regarding the quantification of entropy

1 kg of air in a piston-cylinder apparatus can exchange heat only with a reservoir maintained at 300 K. When 10 kJ of work is done on the air, its state is asserted to change from 1 bar 300 K to 2.5 ...
67 views

### Conical pulley system and transmission ratio (closed)

I tried asking this on other SE forum but i think this is the correct one: Basically our teacher has sent us quite a lot of exercises but I can't get past this one which says: a pulley cone consists ...
164 views

### Derivation of deformation equation given thermal expansion

I'm working on a thermal expansion problem out of Beer & Johnston's Mechanics of Materials and I'm a bit confused by the underlying rationale of one of the steps in the solution process. In the ...
72 views

### Continuity / conservation of mass

Two different incompressible fluids a and b flow into a chamber through two circular ports of area 0.1 and 0.2 m2 respectively. Fluid a is of density 1,200 kgm−3 and flows directly into the chamber ...
140 views

### Vector homework problem [closed]

This is a question from Engineering Mechanics by Shames. I am unable to resolve this as the question mentioned.
119 views

### Dimensions of the wooden post

This question is regarding the following problem from Bending stresses in beams Problem: My solution and hence the answer doesn't match with the answer in the textbook. My Solution: The planks A will ...
156 views

### How is the wire in this problem in pure bending?

Problem: A beam is said to be in pure bending if the bending moment in it remains constant throughout the length. The problem asks to determine the bending moment in the wire. In the solution of the ...
1 vote
171 views

### A problem on beams

Problem - I have interpreted "by hinging them together at B" as following - Now if this is the case, then applying a load on the right beam will have no effect, in my understanding, on ...
343 views

I am searching for a Formal Definition of bandwidth given the transfer function of a system, or the bode plot. Is it the frequency $\omega_b$ in which $$20log|H(j\omega_b)| = -3\text{dB}$$ or $$20log|... 2 votes 2 answers 75 views ### A problem from Damped free Vibrations Problem: I can understand the problem physically that the block is pulled by some amount X so that its displacement at t=0 is X. It is then released from that position so that its velocity at t=0 is ... -1 votes 3 answers 191 views ### how far can two spinning wheels send a tennis ball [closed] so lets say i have two spinning wheels above each other separated by a distance 'x' and I send a tennis ball between them- how do I find the distance the ball would go? using Kinetic energy= ... 4 votes 1 answer 193 views ### How to determine the dynamic response of a spring-mass system? The Problem I have the following system for which I would like to determine its dynamic response, taken from these lecture notes pg.20: where the forcing functions are u_1 = 1-U(t - t_0), u_2=0, ... 0 votes 0 answers 36 views ### Filler material effect on metal Okay, my teacher said that if a filler material is added to metal it is possible with increasing filler content to observer: Yield strength increase, Young modulus decrease, Resilience and elongation ... 0 votes 2 answers 964 views ### How to Find the Magnitude of Force and Direction Give me some tips on how I can find the magnitude of F_3. The hint maybe is the angle of inclination of w axis such that the force components are equal along that axis, my instructor once told me. ... 0 votes 2 answers 662 views ### Maximum induced bending stress within the beam The Maximum induced bending stress within the beam. Given that:$$\frac{My}{I} The beam depth is 300mm, the width is 150mm. The beam is an I section beam with a 5mm wall thickness. My ...
1 vote
I want to make a kalman filter that will estimate the upwash coefficient $C_{\alpha_{up}}$ my state vector: $X_k=[u \ v \ w \ C_{\alpha_{up}} ]^T$ My measurement vector: \$ Z_k =[\alpha_m \ \beta_m ...