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nevsk [136]
3 years ago
9

Vector A extends from the origin to a point having polar coordinates (7, 70ᵒ ) and vector B extends from the origin to a point h

aving polar coordinates (4, 130ᵒ ). Find A · B.
Engineering
1 answer:
yaroslaw [1]3 years ago
8 0

Answer:

13.95

Explanation:

Given :

Vector A polar coordinates = ( 7, 70° )

Vector B polar coordinates = ( 4, 130° )

To find A . B we  will

A ( r , ∅ ) = ( 7, 70 )

A = rcos∅ + rsin∅

therefore ; A  = 2.394i + 6.57j

B ( r , ∅ ) = ( 4, 130° )

B = rcos∅ + rsin∅

therefore ;  B = -2.57i + 3.06j

Hence ; A .B

( 2.394 i + 6.57j ) . ( -2.57 + 3.06j ) = 13.95

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Answer Explanation:

the efficiency of the the engine is given by=1-\frac{T_2}{T_1}

where T₂= lower temperature

           T₁= Higher temperature

we have given efficiency =70%

lower temperature T₂=27°C=273+27=300K

higher temperature T₁=627°C=273+627=900K

efficiency=1-\frac{T_2}{T_1}

                =1-\frac{300}{900}

                 =1-0.3333

                 =0.6666

                 =66%

66% is less than 70% so so inventor claim is wrong

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3 years ago
Which of the following is a possible consequence of poor measurement in construction as stated in the segment?
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Answer:

Decreased risk of structure failure

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You are driving on a roadway with multiple lanes of travel in the same direction, and are approaching an emergency vehicle parke
solmaris [256]

Answer: a. Leave the lane closest to the emergency as soon as it is safe to do so, or slow down to a speed of 20 MPH below the posted speed limit.

Explanation:

Giving a way to the law enforcement vehicle and a medical emergency vehicle is necessary. If one approaches an emergency vehicle parked along the roadway one should change the lane as the vehicle may not move and the driver may also waste his or her time also one should also slow down his or her speed while approaching the vehicle as most of the emergency vehicle are in rush to reach the hospital so the driver should maintain some distance with the medical emergency vehicle.

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What motivated software engineers to move from the waterfall model to the incremental or spiral model
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Answer:

1. They needed to develop multiple components in software programs.

2. The ability to overlap the development to be more evolutionary in nature.

3. The need to be more risk-averse or the unwillingness to take risks led to the use of a spiral model.

Explanation:

Software development life cycle (SDLC) can be defined as a strategic process or methodology that defines the key steps or stages for creating and implementing high quality software applications.

In SDLC, a waterfall model can be defined as a process which involves sequentially breaking the software development into linear phases. Thus, the development phase takes a downward flow like a waterfall and as such each phase must be completed before starting another without any overlap in the process.

An incremental model refers to the process in which the requirements or criteria of the software development is divided into many standalone modules until the program is completed.

Also, a spiral model can be defined as an evolutionary SDLC that is risk-driven in nature and typically comprises of both an iterative and a waterfall model. Spiral model of SDLC consist of these phases; planning, risk analysis, engineering and evaluation.

<em>What motivated software engineers to move from the waterfall model to the incremental or spiral model is actually due to the following fact;</em>

  • They needed to develop multiple components in software programs.
  • The ability to overlap the development to be more evolutionary in nature.
  • The need to be more risk-averse or the unwillingness to take risks led to the use of a spiral model.
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