Answer:
Problem 1 (10 points) In the first homework you were instructed to design the mechanical components of an oscillating compact disc reader. Since you did such a good job in your design, the company decided to work with you in their latest Blue-ray readers, as well. However, this time the task is that once the user hits eject button, the motor that spins the disc slows down from 2000 rpm to 300 rpm and at 300 rpm a passive torsional spring-damper mechanism engages to decelerate and stop the disc. Here, your task is to design this spring-damper system such that the disc comes to rest without any oscillations. The rotational inertia of the disc (J) is 2.5 x 10-5kg m² and the torsional spring constant (k) is 5 × 10¬³NM. Calculate the critical damping coefficient cc for the system. choice of the damper, bear in mind that a good engineer stays at least a factor of In your 2 away from the danger zone (i.e., oscillations in this case). Use the Runge Kutta method to simulate the time dependent angular position of the disc, using the value of damping coefficient (c) that calculated. you Figure 1: Blue-ray disc and torsional spring-damper system.
Answer:
True.
Explanation:
According the engineering flow they don not possess flow energy when they are in rest.
When they are in motion they show a translation energy.
The features if fluids may be different according the variables of pressure and temperature.
Answer:
(a) ΔU = 125 kJ
(b) ΔU = -110 kJ
Explanation:
<em>(a) Suppose that 150 kJ of work are used to compress a spring, and that 25 kJ of heat are given off by the spring during this compression. What is the change in internal energy of the spring during the process?</em>
<em />
The work is done to the system so w = 150 kJ.
The heat is released by the system so q = -25 kJ.
The change in internal energy (ΔU) is:
ΔU = q + w
ΔU = -25 kJ + 150 kJ = 125 kJ
<em>(b) Suppose that 100 kJ of work is done by a motor, but it also gives off 10 kJ of heat while carrying out this work. What is the change in internal energy of the motor during the process?</em>
<em />
The work is done by the system so w = -100 kJ.
The heat is released by the system so q = -10 kJ.
The change in internal energy (ΔU) is:
ΔU = q + w
ΔU = -10 kJ - 100 kJ = -110 kJ
Answer:
Both of them
Explanation:
When creating a marketing plan you need to think of the objective or goals that you have, you should probably always have a running campaign to help the brand itself to be constantly seen by the audience, while at the same time having specific campaigns for the products that you want to push or to promote the most. For example, not all of Nike's ads are aimed to sell more sneakers or sports clothing, some of them are just to keep them on the conversation and growing their brand, while the hype up campaign for the release of a new pair of sneakers or collection is done at the same time. So you should always go for both.
Explanation:
A material can convert from ductile into brittle material by following reasons
1.At low temperature
2.Due to notches present in materials
When temperature is very low then a ductile material starts to behave like brittle material and it leads to failure of the material.
When material consists large number of notches then it losses it ductility and behave like brittle materials.
During the world war second ships are failed because temperature of sea became to low and due to this steel (ductile material) converted into brittle material and failed without giving any warning.
