How much does It cost to make a tracking chip

Which of the following are some of the problems found in city streets?

storchak [24]

Answer: drugs and rushing cars

Explanation: drug dealers are everywhere on city streets nowadays they have been killing young adults

rushing cars or reckless drivers cut curb fast and potentially someone can get hurt they are speeding and not worrying about other people lives at stake

4 0

3 years ago

The viscosity of a fluid is 10 be measured by a viscometer constructed of two 75-cm-long concentric cylinders. The outer diamete

a_sh-v [17]

Answer:

0.023 Pa*s

Explanation:

The surface area of the side of the inner cylinder is:

A = π*d*l

A = π*0.15*0.75 = 0.35 m^2

At 200 rpm the inner cylinder has a tangential speed of:

u = w * r

u = w * d/2

w = 200 rpm * 2π / 60 = 20.9 rad/s

u = 20.9 * 0.15 / 2 = 1.57 m/s

The torque is of 0.8 N*m, this means that the force is:

T = F * r

F = T / r

F = 2*T / d

For Newtoninan fluids with two plates moving respect of each other with a fluid between the viscous friction force would be:

F = μ*A*u / y

Where

μ: viscocity

y: separation between pates

A: surface area of the plates

Then:

2*T / d = μ*A*u/y

Rearranging:

μ = 2*T*y / (d*A*u)

μ = 2*0.8*0.0012 / (0.15*0.35*1.57) = 0.023 Pa*s

5 0

3 years ago

The yield stress of a steel is 250Mpa. A steel rod used for implant in a femurneeds to withstand 29KN. What should the diameter

OleMash [197]

Answer:

r = 1.922 mm

Explanation:

We are given;

Yield stress; σ = 250 MPa = 250 N/mm²

Force; F = 29 KN = 29000 N

Now, formula for yield stress is;

σ = F/A

A = F/σ

Where A is area = πr²

Thus;

r² = 2900/250π

r² = 3.6924

r = √3.6924

r = 1.922 mm

3 0

3 years ago

The time to failure for a gasket follows the Weibull distribution with ß = 2.0 and a characteristic life of 300 days. What is th

Aleks04 [339]

Answer:

64.11% for 200 days.

t=67.74 days for R=95%.

t=97.2 days for R=90%.

Explanation:

Given that

β=2

Characteristics life(scale parameter α)=300 days

We know that Reliability function for Weibull distribution is given as follows

$R(t)=e^{-\left(\dfrac{t}{\alpha}\right)^\beta}$

Given that t= 200 days

$R(200)=e^{-\left(\dfrac{200}{300}\right)^2}$

R(200)=0.6411

So the reliability at 200 days 64.11%.

When R=95 %

$0.95=e^{-\left(\dfrac{t}{300}\right)^2}$

by solving above equation t=67.74 days

When R=90 %

$0.90=e^{-\left(\dfrac{t}{300}\right)^2}$

by solving above equation t=97.2 days

7 0

3 years ago

Problem 10.012 SI A vapor-compression refrigeration cycle operates at steady state with Refrigerant 134a as the working fluid. S

pychu [463]

Answer:

a) 4.1 kw

b) 4.68 tons

c) 4.02

Explanation:

Saturated vapor enters compressor at ( p1 ) = 2.6 bar

Saturated liquid exits the condenser at ( p2 ) = 12 bar

Isentropic compressor efficiency = 80%

Mass flow rate = 7 kg/min

A) Determine compressor power in KW

compressor power = m ( h2 - h1 )

= 7 / 60 ( 283.71 - 248.545 )

= 4.1 kw

B) Determine refrigeration capacity in tons = m ( h1 - h4 )

= 7/60 ( 248.545 - 107.34 )

= 16.47 kw = 4.68 tons

C) coefficient of performance ( COP )

= Refrigeration capacity / compressor power

= 16.47 / 4.1 = 4.02

Attached below is the beginning part of the solution

7 0

2 years ago