Quadratic functions

1003158901

Level: 
C
An object is moving with a constant deceleration in a straight line. Displacement \( s \) (in metres) in time \( t \) (in seconds) is modelled by \( s=24t-3t^2 \). Find the displacement of the object from the moment it starts to decelerate until it stops.
\( 48\,\mathrm{m} \)
\( 144\,\mathrm{m} \)
\( 16\,\mathrm{m} \)
\( 96\,\mathrm{m} \)

1003158902

Level: 
C
The length of a rectangle is \( 4\,\mathrm{cm} \) and width is \( x\,\mathrm{cm} \). The rectangle is divided by vertical crossing line into two parts so that one part is a square with the side of \( x\,\mathrm{cm} \) (see the picture). What is the maximum area of the remaining part of the rectangle?
\( 4\,\mathrm{cm}^2 \)
\( 2\,\mathrm{cm}^2 \)
\( 16\,\mathrm{cm}^2 \)
\( 1\,\mathrm{cm}^2 \)