The efficiency of a transformer is mainly dependent on: a)- Core losses b)- Copper losses c)- Stray losses d)- Dielectric losses

A hair dryer is basically a duct of constant diameter in which a few layers of electric resistors are placed. A small fan pulls

Inessa05 [86]

Answer:

the percent increase in the velocity of air is 25.65%

Explanation:

Hello!

The first thing we must consider to solve this problem is the continuity equation that states that the amount of mass flow that enters a system is the same as what should come out.

m1=m2

Now remember that mass flow is given by the product of density, cross-sectional area and velocity

(α1)(V1)(A1)=(α2)(V2)(A2)

where

α=density

V=velocity

A=area

Now we can assume that the input and output areas are equal

(α1)(V1)=(α2)(V2)

$\frac{V2}{V1} =\frac{\alpha1 }{\alpha 2}$

Now we can use the equation that defines the percentage of increase, in this case for speed

$i=(\frac{V2}{V1} -1) 100$

Now we use the equation obtained in the previous step, and replace values

$i=(\frac{\alpha1 }{\alpha 2} -1) 100\\i=(\frac{1.2}{0.955} -1) 100=25.65$

the percent increase in the velocity of air is 25.65%

6 0

2 years ago

A model shows a city located between a warm ocean and next to coastal mountains. Which statement best describes average weather

DanielleElmas [232]

Answer:

The city will experience high levels of rainfall.

8 0

2 years ago

Read 2 more answers

An airline ticket counter forecasts that 220 people per hour will need to check in. It takes an average of 2 minutes to service

Nadusha1986 [10]

A) Number of agents required to achieve a wait time of 10 minutes or less = 8 agents

B) The number of agents required on duty to reduce cost = 9 agents

Given data :

Arrival rate of customers ( β ) = 220 per hour

Service rate ( mu ) = 60 minutes / 2 minutes = 30 customer per hour

utilization ( rho ) = 220 / 30 ≈ 7

at least 8 server personnel are required for stability of the queue

A) Determine the number of agents required to achieve a wait time of 10 minutes or less per customer

waiting time = 10 - 2 = 8 minutes

number of customers waiting ( ∝ ) = 7 and required server = 8

assuming Lq = 5.2266

Hence the waiting time in line = Lq / arrival rate

= 5.2266 / 220 = 0.0238 hour

= 0.0238 * 60 = 1.428 minutes

Since the waiting time ( 1.428 minutes ) is less than the original waiting time ( 2 minutes ) the number of agents that will achieve a wait time of 10 minutes or less is = 8 agents

B) Determine the number of ticket agents that should be on duty to minimize cost

salary of ticket agent = £12 per hour

cost of customer waiting in queue = £5 per hour per customer

i) When 8 agents are used

waiting time of customers = 0.0238 * 220 = 5.236

waiting cost for customers = 5.236 * 5 = £26.18

employee cost = 8 * 12 = £96

∴ Total cost = 96 + 26.18

= £ 122.18

ii) When 9 agents are used

waiting time for customers = 0.0074 * 220 = 1.628

Wq = 1.6367 / 220 = 0.0074

waiting cost for customers = 1.6367 * 5 = £ 8.1835

assuming Lq = 1.6367

employee cost = 9 * 12 = £ 108

∴ Total cost = 108 + 8.1835 = £ 116.18

From the calculations in ( i ) and ( ii ) the Ideal number of ticket agents that should be on duty to minimize cost should be 9 agents.

Hence we can conclude that A) Number of agents required to achieve a wait time of 10 minutes or less = 8 agents and The number of agents required on duty to reduce cost = 9 agents.

Learn more about cost reduction : brainly.com/question/14115944

6 0

2 years ago

The acceleration due to gravity on the surface of the moon is 1.62m/s^2. The moon's radius is Rm+1738km. A) What is the weight i

Anastaziya [24]

Answer:

weight is 12.6 N

force is 4.05 N

Explanation:

given data

acceleration = 1.62 m/s²

radius = 1738 km

mass = 10 kg

distance = 1738 km

to find out

weight and force

solution

we apply here weight formula that is

weight = mass × acceleration ...................1

put here value

weight = 10 × 1.26

weight = 12.6 N

and

force = mass × An

force = 10 × 1.62 (1738/ 1738+1738)² = 4.05 N

so force is 4.05 N

4 0

2 years ago

A mountain bike has a sprocket and chain drive system designed to adjust the force needed by an operator. The system consists of

Tatiana [17]

Answer:

B. 26 rpm

Explanation:

The sprocket has a diameter of 10 in

The back wheel has a diameter of 6.5 in

One complete revolution formula is : 2πr -------where r is radius

For the sprocket , one revolution = π * D where D=2r

π * 10 = 31.4 in

For the back wheel, one revolution = π* 6.5 = 20.42 in

The pedaling rate is : 40 rpm

Finding the ratio of revolutions between the sprocket and the back tire.

In one revolution; the sprocket covers 31.4 in while the back tire covers 20.42 in so the ratio is;

20.42/ 31.4 = 0.65

So if the speed in the sprocket is 40 rpm then that in the back tire will be;

40 * 0.65 = 26 rpm

8 0

2 years ago