Answer:
Time = 0.317 seconds.
Explanation:
Given the following data;
Distance = 1.65km to meters = 1.65 * 1000 = 1650 meters
We know that the speed of sound in steel is equal to 5200m/s
To find the time to hear the sound of the whistle;
Time = distance/speed
Substituting into the equation, we have
Time = 1650/5200
Time = 0.317 seconds.
Therefore, it will take him 0.317 seconds to hear the sound of the whistle.
Answer:
q = 7.4 10⁻¹⁰ C
Explanation:
a) The magnetic force is given by the expression
F = q v x B
Where the blacks indicate vectors, q is the electric charge, v at particle velocity and B the magnitude of the magnetic field. If the velocity is perpendicular to the magnetic field, the sine is 1
F = q v B
Let's calculate the charge
q = F / vB
q = 1.00 10⁻¹² / 30.0 B
For the magnetic field of the earth we have a value between 25μT and 65μT, an intermediate value would be 45 μT, let's use this value.
q = 1 10⁻¹² / (30 45 10⁻⁶)
q = 7.4 10⁻¹⁰ C
b) In laboratories and modern electronics, currents of up to 1 10⁻⁶ A can be achieved without much difficulty, in advanced and research laboratories currents of up to 1 10⁻¹² can be managed. Load values (coulomb) cannot they are widely used today for work, but 1 mA = 3.6C, so we see that getting loads with the value of 10⁻¹⁰ C implies very small current less than 1 10⁻¹³ A, which only in laboratories of Very specialized can be created. Consequently, from the above it would be difficult to find loads lower than the calculated
The electrostatic charge is the one created by the friction between two surfaces, it is an indicated charge, in this case it would be possible to have better wing loads found from 10⁻¹⁰C
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:




Answer: because of friction it will stop rolling completly
Explanation:
Answer:
The number of digits used to express a measured or calculated quantity. By using significant figures, we can show how precise a number is
Explanation: