Answer:
(a)
(b)
(c) 1 s
(d) 20 m
(e) 1 m
(f)
(g)
(h)
(i)
(j)
(k)
(l)
(m)
Explanation:
Since <em>x</em> is measured in meters and <em>t</em> in seconds, constants <em>a </em>and <em>b</em> must have units that gives meters when multiplied by square and cubic seconds respectivly, so that would mean for <em>a </em>and
for <em>b</em>.
We can get the velocity <em>v </em>equation by deriving the position with respect to <em>t</em>, which gives:
And the acceleration <em>a</em> equation by deriving again:
Now for getting the maximun position between 0 and 4, we must find to points where the positions first derivate is equal to cero and evaluate those points. That is <em>v=0</em>, which gives
For <em>t = 0</em>,<em> x = 0</em> so the maximun position is archieved at 1 second, which gives <em>x = 1 meter</em>.
For obtaining it's displacement <em>r</em>, we can integrate the velocity from 0 seconds to 4 seconds, which gives the mean value of the position in that interval:
For the remaining questions, we just replace the values of <em>t</em> on the respective equations.