Answer:
Force, F = 500 N
Explanation:
Given that,
Power expanded, P = 1000 W
Distance moved by piano, d = 10 m
Time taken, t = 5 s
To find,
The force exerted by the person
Solution,
The rate at which the work is being done is called power delivered. Its formula is given by:

W is the work done, W = F × d

On rearranging the above formula to find F as :


F = 500 N
Therefore, the force exerted on the person is 500 N. Hence, this is the required solution.
Answer:
a)
, b)
, c) 
Explanation:
a) The turbine is modelled by means of the First Principle of Thermodynamics. Changes in kinetic and potential energy are negligible.

The mass flow rate is:

According to property water tables, specific enthalpies and entropies are:
State 1 - Superheated steam




State 2s - Liquid-Vapor Mixture




The isentropic efficiency is given by the following expression:

The real specific enthalpy at outlet is:



State 2 - Superheated Vapor




The mass flow rate is:


b) The temperature at the turbine exit is:

c) The rate of entropy generation is determined by means of the Second Law of Thermodynamics:




The power ratio of a washing machine at 80 decibels is 10⁸ or 100,000,000.
<h3>What is the power ratio of a sound of 80 decibels?</h3>
Sound is a form of disturbance created by the vibrations of the medium and which travels across the medium in wave form.
A measure of sound intensity is decibels.
Decibels are a measure of sound on a logarithmic scale, where the number in front of the zero represents the number of powers of 10.
Therefore, the power ratio of a washing machine at 80 decibels will be 10⁸.
In conclusion, sound are vibrations which transmit energy.
Learn more about sound at: brainly.com/question/1199084
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Yes its D. Molecules is the answer because A molecule is an electrically neutral group of two or more atoms held together by chemical bonds.
Answer:
When we go go up a hill,we will be going against the gravitational force. So we experience a gravitational pull towards the ground. So it is necessary to speed up the car while moving up hill.
Explanation: