Question

What is the total displacement???

Answer 1

Answer: 562.5 m

$Displacement = velocity \times time$= area under the curve in velocity-time graph

The area of the quadrilateral formed by the graph is given by:

$A=\frac{(a+b)}{2} h$

where, a and b are two parallel sides of the quadrilateral, h is the perpendicular distance between the two parallel sides.

from the given graph,

$a=10 m/s$

$b=35 m/s$

$h=25 s$

Hence, $A= \frac{(10+35) m/s}{2}\times 25 s=562.5 m$

The area under graph = 562.5 m. Hence, the total displacement is 562.5 m.

Answer 2

Displacement (between time 0 and time 25) is the area under the velocity time curve, i.e. ∫ vdt.
Here, v(0)=10, v(25)=34 (approx.)
Therefore 
displacement = (1/2)(10+34 m/s)*(25-0) s   [ trapezoid area ]
=550 m