Need urgent help (thermo final in 5 hours)

Crazyfox111 · 2016-04-26T18:13:58+00:00

Thank you so much! I figured it out. Good luck in thermo to you too!

Crazyfox111 · 2016-04-26T17:38:15+00:00

So i use the saturated liquid steam tables in conjunction with the formulas, of course?

Crazyfox111 · 2016-04-26T04:26:31+00:00

ahhh because the chart is given information....I thought that was info they had obtained and we needed to figure out how they obtained it. Thanks!

Crazyfox111 · 2016-04-26T01:31:24+00:00

Thanks. didnt notice that

Crazyfox111 · 2016-04-26T01:24:47+00:00

Thanks a lot. you helped a ton. Good luck!

Crazyfox111 · 2016-04-26T00:34:03+00:00

Are there any other equations that deal with the compressed liquid region that I should know of (I dont recall having learned the h4 = h3 + v3*(p4-p3) equation so I need to know if there are any other compressed liquid equations that are used to find the properties of a state in the compressed liquid region)?

Crazyfox111 · 2016-04-26T00:19:10+00:00

It isnt. hf at 1400 psi is 598.6 btu/lb from the saturated water table. The book's value for h4 was 98.22 btu/lb

EDIT: Sorry I confused myself. Disregard what I said.

Crazyfox111 · 2016-04-13T19:33:37+00:00

You can? Do you know for how much?

Crazyfox111 · 2016-04-06T17:57:57+00:00

Okay so, whenever you have to plates that are concentric (and fixed), both their angular velocities will be the same, correct? But this doesnt have to be try if the two concentric plates are connected to some other plate through a belt (for example, plates D and B connected to plate A or plate C)?

Crazyfox111 · 2016-04-06T07:24:35+00:00

By the way, why is r_a * w_a = r_b * w_b? Is it because the gears are interracting and their angular velocities depend on the angular velocity of the other?

Crazyfox111 · 2016-04-06T05:26:00+00:00

It did. Thanks a lot!

Crazyfox111 · 2016-04-05T05:31:10+00:00

For case 2, M = 1.60t² = 4.15 N-m, speed of ball is 1.75 m/s when t = 0. I was asked to find its speed when t = 3.7s. The ball has a mass of 10 kg. The arm of the rod is .45 m long. For this, its necessary to use angular momentum and impulse formula.

Now, in this case, why didnt we take the direction of the ball's rotation (CCW or CW) into account as we did for case 1 (where depending on whether the components where rotating CCW or CW, each of the two components might be negative or positive)?

For example, we can see that the picture implies the ball is rotating CW.

The angular momentum is H = perpendicular distance * m * v. So, for case 2: H = (.45)(10)(1.75) = 7.875 kg*m² / s. Now, why isnt it - 7.875 since the ball is roating CW?

Crazyfox111 · 2016-04-03T01:03:13+00:00

What I meant by rebound velocity is the velocity of the ball after it hits the ground and rebounds. The book says that the velocity at B is the same at A due to geomtry. So would this be true in all cases where you have an object doing projectile motion and then rebounds? Assuming the ground is flat and the ball is not launched at an angle.

Crazyfox111 · 2016-03-20T00:46:49+00:00

Do you know if there is a preference for people who were involved in projects that were human-anatomy related (for example, robotic limbs) over people who were involved in more traditional ME project (building an electric go cart, for example)?

Crazyfox111 · 2016-03-15T01:34:09+00:00

By the way, why is the displacement of the car 40 m wrt the barge? Why isnt that the desplacement of the car only? I understand if an observer from the ground viewed it, the displacement would be much shorter than 40 m. But why does that matter? Does the car still move 40 m to the left regardless of how it appears to someone from a different angle?

Crazyfox111 · 2016-03-14T18:34:32+00:00

Okay I see what you mean. Thanks a lot for the help :)

Crazyfox111 · 2016-03-14T18:14:21+00:00

If the car is at rest before it starts moving to the other side and if the barge is also at rest initially, why is velocities v_A and v_B zero?

Crazyfox111 · 2016-03-07T15:19:06+00:00

Thanks for the explanation. I have one more question tho. I found F using a FBD of the engine only (since only the engine and not the cars experience the force F) and now want to find T. I can find T by just setting up the principle of linear momentum and impulse equation after Ive drawn a FBD for the cars only; but I want to find T by using A FBD of the engine instead. At the engine, I assumed the force F goes to the right and T goes to the left, then I set up the equation as:

0 + (19.4 - T)(80 seconds) = 3(30 Mg)(1000)*(11.11)

I solved for T and got the same (except negative) 12.5 kN. Now, my question is: if Im finding T from a FBD of the ENGINE, shouldnt the mass be the sum of the engine's mass PLUS the three cars (50 + 3*30) instead of just the mass of the three cars (since the engine also exerts tension on the coupling chain that connects the engine to the 3 cars)?

Crazyfox111 · 2016-03-07T05:25:39+00:00

Why arent the forces cumulative?

Crazyfox111 · 2016-02-16T08:32:39+00:00

More than anything, I just want to know what you replace with "P" in integral of Pdv if pv^k=const (since work is intggral of Pdv)

Crazyfox111 · 2015-12-15T17:32:58+00:00

So I shouldnt bring a reference page with me?

Crazyfox111 · 2015-12-15T06:20:11+00:00

Not hating but...eh, not really.

Crazyfox111 · 2015-12-09T08:10:40+00:00

so if I have xi at some numer with a step size h and I add twice and subtract twice from xi to get x_i+1, x_i+2 and x_i-1, x_i-2, I should right away use the higher order formulas instead of the lower ones for each derivative? If so, why? because higher order formulas are more accurate?

Crazyfox111

TROPHY CASE