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.
Positive: 690
Negative: -30
Answer:
45.1
Step-by-step explanation:
The original amount is 82
But the wrong amount is 45
So we will have to calculate the percentage for the error
82-45
37
So %error= 37/82 ×100
=3700/82
=45.121~45.1( to nearest tenth)
So the final answer is 45.1%
180- 113 = 67
180- 67= 113
<5= 67
<2=113