Question

what is velocity of body at 15 secs

Answer 1

The velocity of the body at 15 second is 50m/s.

Answer 2

velocity of the body at t=15 sec is given by the area under the acceleration time graph.

area under the graph=area of rectangle 1 + area of rectangle 2+ area of rectangle 3

area of rectangle 1=5*5=25

area of rectangle 2=5*0=0

area of rectangle 3=5*5=25

net are=25+0+25

=50 m/s

Hope this helps.