Answer: The correct option is A.
Explanation:
Inertia is a state of an object or body to maintain its state. It resists any change in its state.
Newton's first law of inertia: When an objects is in state of motion, it will remain its state of motion or if it is in state of rest then it will remain in rest unless it is acted upon by external motion.
In the given options, a ball sits motionless on the ground is good example of Newton's first law motion. No external force is acting in this case.
In options (B), (C) and (D) , the external force is acting.
Therefore, the correct option is A.
Answer:
Correct answer: m₂ = 1,950 g
Explanation:
When mixing the liquid, in this case water, at different temperatures, the warmer liquid will cool and the cooler will warm up until their temperatures equalize.
The amount of heat that the second fluid (water) releases is equal to the amount of heat that the first fluid (water) receives in this spontaneous process.
Q₁ = Q₂
Q₁ = m₁ c (t - t₁) and Q₂ = m₂ c (t₂ - t)
where are they: m₁ = 750 g, t₁ = 10°C, t₂ = 100°C, t = 75°C, m₂ = ?
m₁ c (t - t₁) = m₂ c (t₂ - t) \ : c
Since water is the liquid in question, it has the same specific heat capacity. Therefore, we will divide both sides of the equation by c and get:
m₁ (t - t₁) = m₂ (t₂ - t) => m₂ = m₁ (t - t₁) / (t₂ - t) =>
m₂ = 750 · (75 - 10) / (100 - 75) => m₂ = 750 · 65 / 25 = 1,950 g
m₂ = 1,950 g
God is with you!!!
D. The noise of a car horn. Hope this helps! Please comment if it does!
Answer:
“I had to cut off the third prong on the electrical plug so that it would fit in the extension cord.”
Explanation:
A good method to find the customer at greater risk of receiving an electric shock is to discard the options.
If we analyze the fourth option "I always make sure that I am standing in a dry area before operating electrical equipment.", we will see that the customer minimizes the risk of electric conduction through a fluid. This precaution also minimizes the risk of electric shock.
The third option "I always read the owner’s manual when I purchase a new electrical appliance." It tells us that the customer knows how to properly use the electrical equipment that manipulates and knows the do and do not of such devices, so the risk of electric shock is reduced.
In the second option, "My bread got stuck in my toaster this morning, and I unplugged it before trying to remove it." The customer made sure to interrupt the electric flow to the device before proceeding and try to remove the jammed bread. If there is no electric current, there will be no electric shock to the customer.
The first option "I had to cut off the third prong on the electrical plug so that it would fit in the extension cord." It tells us that the client altered the cord extension in an inappropriate manner, since the equipment is not designed to work with two prongs. Because the design conditions are not being met, it is possible that the equipment malfunctions and this malfunction could result in the customer receiving an electric shock.
I hope the explanation was clear for you. If you have any further question, I'll be happy to assist you. :D
The question is incomplete. The complete question is :
If the entire population of Earth were transferred to the Moon, how far would the center of mass of the Earth-Moon population system move? Assume the population is 7 billion, the average human has a mass of 65 kg, and that the population is evenly distributed over both the Earth and the Moon. The mass of the Earth is 5.97×1024 kg and that of the Moon is 7.34×1022 kg. The radius of the Moon’s orbit is about 3.84×105 m.
Solution :
Given :
Mass of earth, 
Mass of moon, 
Mass of each human, 
Therefore mass of total population, 

Let the earth is at the origin of the coordinate system. Then,
Since 

Hence if we shift all the population on the moon there will be negligible change in the mass of the moon and earth. Hence there will not be any significant shift on the centre of mass. i.e.


from the earth.