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:
1.692 m/min
Step-by-step explanation:
Let
be the angle between the two sides and x be the length of the third side. By cosine rule,


We differentiate x with respect to
by applying chain rule.

Rate of change of
is 2

Rate of change of x is


At 60°,

<span><span>(<span>sinx</span>−<span>tanx</span>)</span><span>(<span>cosx</span>−<span>cotx</span>)</span></span>
<span>=<span>(<span>sinx</span>−<span><span>sinx</span><span>cosx</span></span>)</span><span>(<span>cosx</span>−<span><span>cosx</span><span>sinx</span></span>)</span></span>
<span>=<span>sinx</span><span>(1−<span>1<span>cosx</span></span>)</span><span>cosx</span><span>(1−<span>1<span>sinx</span></span>)</span></span>
<span>=<span>sinx</span><span>(<span><span>cosx</span><span>cosx</span></span>−<span>1<span>cosx</span></span>)</span><span>cosx</span><span>(<span><span>sinx</span><span>sinx</span></span>−<span>1<span>sinx</span></span>)</span></span>
<span>=<span><span>sinx</span><span>cosx</span></span><span>(<span>cosx</span>−1)</span><span><span>cosx</span><span>sinx</span></span><span>(<span>sinx</span>−1)</span></span>
<span>=<span>(<span>cosx</span>−1)</span><span>(<span>sinx</span>−1<span>)</span></span></span>
The answer will be D. 7/10 because you have 10 numbers and you want to have a number greater than 3 so it would be 10-3=7 and 7 would go over 10 because there are 7 numbers greater than 3 but less than 10.