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

.
The slope:
m = ( y2 - y1 ) / ( x2 - x1 ) = ( 8 2 ) / ( 3 - 2 ) = 6 / 1
m = 6 ( we have the same slope for AB and A`B` )
AB = √[( 3 - 2 )² + ( 8 - 2 )²] = √37
A`B` = 3.5 √37 = 21.29
We have that the spring is going to have a sin or a cos equation. We have that the maximum distance of the spring is 6 inches and it is achieved at t=0. Let's fix this as the positive edge. Until now, we have that the function is of the form:
6sin(at+B). We have that the period is 4 minutes and hence that the time component in the equation needs to make a period (2pi) in 4 minutes. Thus 4min*a=2p, a=2p/4=pi/2. In general, a=2pi/T where a is this coefficient, T is the period. Finally, for B, since sin(pi/2)=1, we have that B=pi/2 because when t=0, we have that 6sin(B)=6. Substituting, we have f(t)=6sin(pi*t/2+pi/2)=6cos(pi*t/2)
by trigonometric identities.
Answer:
3 1/2 hours
Step-by-step explanation:
This is a problem in units conversion. We want to get from bags to hours by way of minutes per bag. One bag takes an effort of 2/3 person·minute, so we need to divide the total effort by the number of persons and convert minutes to hours.
(1575 bags)×(2/3 person·min/bag)/(5 person)/(60 min/h)
= (1575)(2/3)(1/5)(1/60) h = 3.5
It will take the 5 of them about 3 1/2 hours to prepare 1575 bags.