Given figure is Time -velocity graph that indicate acceleration .
Now, according to problem
1) A graph line is parallel to time axis i.e. velocity is not changing with passes of time , so acceleration (a) = 0.
Here,
acceleration (a)= 0
time (t)= 20 sec
starting speed (u)= 40 m /s
final speed (v)= 40m /s
distance covered( s)= ?
Now using formula for linear motion ,we get
Answer is 800m
2) For graph line B---
Starting speed(u)= 25 m/s ( when time =0)
final speed (v) = 50 m/s (when time =20 s)
time (t)= 20 sec
acceleration (a)= ?
distance travelled (s)= ?
Now acceleration is given by
Again distance travelled in 20 s is given by
Answer is a= 1.25m/s² and s= 750m
3) when t= 20 sec then distance travelled by A=800m and distance travelled by B= 750 m . Therefore A is ahead of B
4) distance travelled by car A in 40 sec is given by
Now distance travelled by B is given by