To solve this we are going to use the formula fro the force applied to a spring:

where

is the spring constant

is the extension
Since we know the

, we can replace that in our formula and solve for

:


where

is the acceleration

is the spring constant

is the extension

is the mass
We know for our problem that

,

, and

. So lets replace those values in our formula to find

:



We can conclude that the acceleration of the block when s=0.4m is

.
Answer:
C
Step-by-step explanation:
Stay safe hope this helps
Answer:
NGC 1427A has no general shape, so it is an irregular galaxy. U has a bulge in the center and arms, so it is a spiral galaxy. They are similar in that both contain plenty of dust and gas. Both also have active star-forming sites.
Step-by-step explanation: Got it right on the test
If he bikes for 10 miles per hour and 8 miles per hour for the same distance x miles, he went 10 miles per hour for x/10 hours, as Distance = Rate*Time and on the way back he would go for x/8 hours. So then he went 2x distance, in x/8 + x/10 hours. Since x/8 + x/10 = 10x/80 + 8x/80 = 18x/80 = 9x/40, he went 2x miles in 9x/40 hours. this can be converted into a rate with the above equation Distance = Rate*Time, so 2x=(9x/40) * Rate, thus we divide by 9x/40 on both sides to get 80x/9x = Rate, the x cancels out, and we get 80/9 Miles per hour.
1/2 of the books are science books because once you convert the other two books you get 2/6 +1/6= 1/2 so the science books will be the other half.