For this case we have the following equation:

Where,
w: The weight of a spring in pounds
E: the energy stored by the spring in joules.
Substituting values we have:

Making the corresponding calculation:
Answer:
the approximate weight of the spring in pounds is:
Answer:
18.0
Step-by-step explanation:
Note the tenth place value (underlined and bolded): 18.<u>0</u>49
Look at the number to the direct right of the tenth place value (or the hundredth place value in this case). It is a 4.
Note the rules of rounding. If the number:
1) is 5 or greater, round up.
2) is 4 or less, round down.
In this case, it is 4, so you will round down.
18.049 rounded to the nearest tenth is 18.0
~
No, because, using the Pythagorean Theorum:
6^2+8^2=9^2
36+64 IS NOT = TO 81
Answer:
x=6
Step-by-step explanation:
7x =42
7 7
x=6
Divide 7 on both sides