Friction is the opposition offered to the movement of a surface on another and depends on the nature of the surfaces in contact.
<h3>What is friction?</h3>
The term friction refers to the opposition that is offered by surfaces in contact when they move over each other. The question is incomplete but I will try to help you the much I can.
Now recall that fricton only depends on the nature of the surfaces in contact. The friction is te reason when heat is provides in the moving parts of machines.
Learn more about friction: brainly.com/question/15117038
Below are the answers:
(a) Ep = mass x gravitational acceleration x height
<span>= 2kg x 9.8ms-2 x 3m </span>
<span>= 58.8J </span>
<span>(b) F = mg </span>
<span>= 2kg x 9.8ms-2 </span>
<span>= 19.6N </span>
<span>W = Fd </span>
<span>= 19.6N x 3m </span>
<span>= 58.8J
</span>
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Answer:3.49 m/s
Explanation:
Given
Speed of marble at Bottom 
Diameter of loop 
As Energy is conserved therefore Energy at top is equal to energy at bottom

,where
is the velocity at bottom







Answer:
a 
b
Explanation:
Generally the force constant is mathematically represented as

substituting values given in the question
=> 
=> 
Generally the workdone in stretching the spring 3.5 m is mathematically represented as

=> 
=> 
Generally the workdone in compressing the spring 2.5 m is mathematically represented as
=>
=>