Answer:
8 Joule
Step-by-step explanation:
Mass of block = 2 kg
Displacement = x = 800 mm = 0.8 m
Spring constant = k = 25 N/m
Potential Energy of a spring
Work done = Difference in Potential Energy
Work Done = Δ P.E.
⇒P.E. = 0.5×25×0.8²
⇒P.E. = 8 Nm = 8 Joule
Here already the spring constant and displacement is given so the mass will not be used while calculating the potential energy.
Ken earns 54 dollars at his part-time job on Friday
Given that Total amount earned by ken and his wife at their part-time job on Friday= $174
Money earned by ken= x dollars
Money earned by ken's wife = (2x+12) dollars
Total amount earned by ken and his wife at their part-time job on Friday= x dollars + (2x+12) dollars
(x + 2x + 12 ) dollars = $ 174 ( addition of ken and ken's wife income and total amount earned by ken and his wife at their part-time job on Friday is $174)
(3x + 12 ) dollars = $ 174
3x=$162
x=
x= 54 dollars
Therefore,54 dollars were earned by ken at his part-time job on Friday
Hence,Ken earns 54 dollars at his part-time job on Friday
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