Answer:
The force that happens between two particles with mass
The two spheres have opposite charges.
<h3 /><h3 /><h3>What are types charge?</h3>
- A charge can be negatively charged or positively charged.
- When two charges have opposite signs, that is positive and negative signs, the two charges will attract each other.
- When the two charges have the same sign, it causes repulsion.
When a positive charge points downwards ↓ and the negative charge points upwards ↑, this causes attraction and shows that the two charges are different.
Thus, we can conclude that the two spheres have opposite charges.
Learn more about attraction and repulsion of charges here: brainly.com/question/2396080
Answer:
The temperature of the metal is 
Explanation:
From the question we are told that
The mass of the metal is 
The specific heat of the metal is 
The mass of the oil is 
The temperature of the oil is 
The specific heat of oil is 
The equilibrium temperature is 
According to the law of energy conservation
Heat lost by metal = heat gained by the oil
So
The quantity of heat lost by the metal is mathematically represented as

=> 
Where
the temperature of metal before immersion
The negative sign show heat lost
The quantity of gained t by the metal is mathematically represented as

=> 
So

substituting values

=> 
The speed of the pin after the elastic collision is 9 m/s east.
<h3>
Final speed of the pin</h3>
The final speed of the pin is calculated by applying the principle of conservation of linear momentum as follows;
m1u1 + mu2 = m1v1 + m2v2
where;
- m is the mass of the objects
- u is the initial speed of the objects
- v is the final speed of the objects
4(1.4) + 0.4(0) = 4(0.5) + 0.4v2
5.6 = 2 + 0.4v2
5.6 - 2 = 0.4v2
3.6 = 0.4v2
v2 = 3.6/0.4
v2 = 9 m/s
Thus, The speed of the pin after the elastic collision is 9 m/s east.
Learn more about linear momentum here: brainly.com/question/7538238
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The distance decreases as the time increases