<span>1) at rest his
weight is 840 N
=> 840N = mass * g => mass = 840 N / g = 840 N / 9.8 m/s^2 = 85.7 kg
2) as the elevator rises, his weight increases to 1050 N,
The reading of the scale is the norma force of it over the body of the person.
And the equation for the force is: Net force = mass * acceleration = normal force - weight at rest
=> mass * acceleration = 1050 N - 840 N = 210 N
acceleration = 210 N / mass = 210 N / 85.7 kg = 2.45 m/s^2 (upward)
3)  when the elevator slows to a stop at the 10th
floor, his weight drops to 588 N
=>  mass * acceleration = 588 N - 840 N = - 252 N
=> acceleration = - 252 N / 85.71 kg = - 2.94 m / s^2 (downward)
Answer: 
Acceleration at the beginning of the trip 2.45 m/s^2 upward
Acceleration at the end of the trip 2.94 m/s^2 downward
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Answer:
Compare brands first, but purchase the one that has lots of commercial advertisements, Compare ingredients and purchase the brand that is safe to use with soft contact lenses, Compare prices and purchase the most inexpensive brand.
Explanation:
 
        
             
        
        
        
Explanation:
1 mega Hertz = 1000000 hertz
 
        
             
        
        
        
The fraction of the water must evaporate to remove precisely enough energy to keep the temperature constant when water at 37°c has a latent heat of vaporization of lv = 580 kcal/kg is 2.58 times 10 to the minus 3.
Vaporization is the process by which a substance is transformed from its liquid or solid state into its gaseous (vapour) state. Boiling is the term for the vaporization process when conditions permit the creation of vapour bubbles within a liquid. Sublimation is the process of directly converting a solid to a liquid.
Boiling and evaporation are the two processes that cause vaporization. Evaporation is the process by which a liquid body's surface changes from a liquid to a gas, as in the case of a drop of water on hot concrete evaporating into a gas. A liquid is said to be boiling when it is heated to the point at which it begins to give off steam, as when you boil water on a stove. The process of converting a substance from its liquid or solid state into its gaseous (vapour) state is known as vaporization.
To learn more about vaporization please visit - brainly.com/question/12625048
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Answer:
The value of the average convection coefficient is 20 W/Km².
Explanation:
Given that,
For first object,
Characteristic length = 0.5 m
Surface temperature = 400 K
Atmospheric temperature = 300 K
Velocity = 25 m/s
Air velocity = 5 m/s
Characteristic length of second object = 2.5 m
We have same shape and density of both objects so the reynold number will be same,
We need to calculate the value of the average convection coefficient
Using formula of  reynold number for both objects



Here, 


Put the value into the formula


Hence, The value of the average convection coefficient is 20 W/Km².