Ask question

Ask question

All categories

3 years ago

5

The acceleration (in m/s^2) of a linear slider (undergoing rectilinear motion) within a If the machine can be expressed in terms

of its velocity (in m/s) and is given by α=1/4v^2 = if the slider starts at rest, find the time at which its velocity is 3.3 m/s.

1 answer:

Inga [223]3 years ago

6 0

Answer:

47.91 sec

Explanation:

it is given that $\alpha =\frac{1}{4v^{2}}$

at t=0 velocity =0 ( as it is given that it is starting from rest )

we have to find time at which velocity will be 3.3 $\frac{m}{sec^{2}}$

we know that $\alpha =\frac{dv}{dt}=\frac{1}{4v^{2}}$

$4v^{2}dv=dt$

integrating both side

$\frac{4v^{3}}{3}=t+c$ ---------------eqn 1

at t=o it is given that v=0 putting these value in eqn 1 c=0

so $\frac{4v^{3}}{3}=t$

when v= 3.3 $\frac{m}{sec^{2}}$

t= $\frac{4}{3}\times 3.3^{3}$

=47.91 sec

You might be interested in

Write a function named "read_prices" that takes one parameter that is a list of ticker symbols that your company owns in their p

ohaa [14]

Answer:

import pandas pd

def read_prices(tickers):

price_dict = {}

# Read ingthe ticker data for all the tickers

for ticker in tickers:

# Read data for one ticker using pandas.read_csv

# We assume no column names in csv file

ticker_data = pd.read_csv("./" + ticker + ".csv", names=['date', 'price', 'volume'])

# ticker_data is now a panda data frame

# Creating dictionary

# for the ticker

price_dict[ticker] = {}

for i in range(len(ticker_data)):

# Use pandas.iloc to access data

date = ticker_data.iloc[i]['date']

price = ticker_data.iloc[i]['price']

price_dict[ticker][date] = price

return price_dict

7 0

3 years ago

Steam enters a turbine steadily at 7 MPa and 600°C with a velocity of 60 m/s and leaves at 25 kPa with a quality of 95 percent.

Rufina [12.5K]

Answer:

a) $\dot m = 16.168\,\frac{kg}{s}$ , b) $v_{out} = 680.590\,\frac{m}{s}$ , c) $\dot W_{out} = 18276.307\,kW$

Explanation:

A turbine is a steady-state devices which transforms fluid energy into mechanical energy and is modelled after the Principle of Mass Conservation and First Law of Thermodynamics, whose expressions are described hereafter:

Mass Balance

$\frac{v_{in}\cdot A_{in}}{\nu_{in}} - \frac{v_{out}\cdot A_{out}}{\nu_{out}} = 0$

Energy Balance

$-q_{loss} - w_{out} + h_{in} - h_{out} = 0$

Specific volumes and enthalpies are obtained from property tables for steam:

Inlet (Superheated Steam)

$\nu_{in} = 0.055665\,\frac{m^{3}}{kg}$

$h_{in} = 3650.6\,\frac{kJ}{kg}$

Outlet (Liquid-Vapor Mix)

$\nu_{out} = 5.89328\,\frac{m^{3}}{kg}$

$h_{out} = 2500.2\,\frac{kJ}{kg}$

a) The mass flow rate of the steam is:

$\dot m = \frac{v_{in}\cdot A_{in}}{\nu_{in}}$

$\dot m = \frac{\left(60\,\frac{m}{s} \right)\cdot (0.015\,m^{2})}{0.055665\,\frac{m^{3}}{kg} }$

$\dot m = 16.168\,\frac{kg}{s}$

b) The exit velocity of steam is:

$\dot m = \frac{v_{out}\cdot A_{out}}{\nu_{out}}$

$v_{out} = \frac{\dot m \cdot \nu_{out}}{A_{out}}$

$v_{out} = \frac{\left(16.168\,\frac{kg}{s} \right)\cdot \left(5.89328\,\frac{m^{3}}{kg} \right)}{0.14\,m^{2}}$

$v_{out} = 680.590\,\frac{m}{s}$

c) The power output of the steam turbine is:

$\dot W_{out} = \dot m \cdot (-q_{loss} + h_{in}-h_{out})$

$\dot W_{out} = \left(16.168\,\frac{kg}{s} \right)\cdot \left(-20\,\frac{kJ}{kg} + 3650.6\,\frac{kJ}{kg} - 2500.2\,\frac{kJ}{kg}\right)$

$\dot W_{out} = 18276.307\,kW$

6 0

3 years ago

Explain why advances in technology can actually create more problems for engineers.

andrew11 [14]

Explanation:

Engineering is science in practical terms. It is the application of scientific findings in problem solving and creating a better world.

How does technological advancements create more problems for engineers?

Loss of job to automation: the world is driving at automating work processes through the use of specially designed and crafted machinery. Work is now properly being done using machines with little to no human input in the whole process. This is a huge let off for engineers. Engineers have to compete with machines which are their own inventions for jobs now.
Fast paced work environment: machines can handle work more efficiently and faster than the people making them. There is an increasing race between engineers and their own inventions today for better product delivery. Unless a machine is faulty, they are more productive and efficient than man. This can cause engineers to want to catch up with their own inventions leading to a work life of stress.
Environmental problems they cannot solve: most inventions use components from the environment. They release effluents that are very difficult to be properly disposed or stored. This is a huge problem for engineers and can lead to ethical calls from the government and the populace. In short, they can create problems they are expected to solve but cannot solve.
Social problems: engineers can be portrayed as terrible beings for their own inventions. This leads to psychological problems on a good and creative invention. For example, rare earth metals in DR Congo are instrumental in making solar panels, but mining of these metals have forced several thousands of people into hard and intense labor on mines; there is a call on technological firms to stop exploiting people this way for their own gains.
Misuse of technology: any good technology can be put into the wrong use. A nuclear reaction can be packaged into a bomb and also, it can be the center of electricity generation on a commercial scale. How can engineers solve this kind of problem? Technological inventions are subjective in their usage.

Learn more:

New technology brainly.com/question/5768621

#learnwithBrainly

3 0

3 years ago

Transmission cleaners are used: A) Only in conjunction with fuel system cleanersB) Only in the colder monthsC) By themselvesD) I

valentina_108 [34]

Answer: D

Explanation: When you change your transmission fluid you change your filter. When you do that you clean where the filter was. Then you can put the new filter on and the new fluid.

5 0

3 years ago

Read 2 more answers

For automobile engines, identify the best choice of motor oil.

Vlad1618 [11]

Answer:

C. Low viscosity for Maine in the winter and high viscosity for Florida in the summer.

Explanation:

The choice of motor oil or engine oil depends on the type of engine and also on the type of climate on which the engine runs.

In winter climates, we should use oil with low viscosity as at lower temperatures, the it flows more readily if its viscosity is low.

But the summer season needs a relatively thicker oil so as to reduce the thinning effect of the oil out of the engine.

Thus for Maine in the winter season, we need a low viscosity oil and for Florida a high viscosity oil in the summer season.

Therefore, option (c) is correct.

6 0

2 years ago