The top pair of pliers failed to loosen a stubborn bolt, but the bottom pair successfully removed it. Because the contact between the bolt and the pliers working surface is less.
<h3>What is mechanical advantage ?</h3>
Mechanical advantage is a measure of the ratio of output force to input force in a system, it is used to obtained efficiency of the given mechanical machine.
The efficiency to open the stubborn bolt depends upon the contact between the working surface of the pliers and the bolt.
The contact between the bolt and the top pair of pliers working surface is less. Its mechanical advantage is less.
Hence, the top pair of pliers failed to loosen a stubborn bolt, but the bottom pair successfully removed it.
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10.67m/s²
32N
Explanation:
Given parameters:
Mass of the body = 3kg
velocity of the mass = 4m/s
radius of circle = 0.75m
Unknown:
centripetal acceleration = ?
centripetal force = ?
Solution:
The centripetal force is the force that keeps a radial body in its circular motion. It is directed inward:
Centripetal acceleration = 
v is the velocity of the body
r is the radius of the circle
putting in the parameters:
Centripetal acceleration = 
Centripetal acceleration = 10.67m/s²
Centripetal force = m
m is the mass
Centripetal force = mass x centripetal acceleration
= 3 x 10.67
= 32N
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Acceleration brainly.com/question/3820012
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The beginning development of a
star is marked by a supernova explosion, with the gases present in the nebula
being forced to scatter. As the star shrinks, radiation of the surface increases
and create pressure on the outside shell to push it away and forming a
planetary nebula or white dwarf.
Answer:
Part a)

Part b)

Explanation:
Part a)
As we know that both charge particles will exert equal and opposite force on each other
so here the force on both the charges will be equal in magnitude
so we will have

here we have

now we have

Part b)
Now for the force between two charges we can say

now we have

now we have

Answer:
The specific heat of liquid water is about 4184 J/kg at 20 °C.
So, <u>Correct choice</u> - [C] 4186 J / kg ° C