18. (a) Derive the equation of motion v = u +at, using graphical method.

(b) A train starting from rest attains a velocity of 72 km/h in 5 minutes. Assuming the acceleration is uniform, find

1. 1. the acceleration.
   2. the distance travelled by the train for attaining this velocity.

 

Dear student ( B) initial velocity,u = 0 m/s Final velocity,v = 72 Km/hr = (72*5)/18 m/s = 20 m/s Time,t = 5 minutes = 5*60 = 300 seconds Acceleration,a = ? Distance,s = ? i) a= v-u/t = 20-0/300= 1/15 m/sec2 ii) From second law of motion s = ut + 1/2 at2 s = (0*300) + 1/2 * 1/15 * 300 * 300 s = 3000m = 3 Km. For rest of the queries please repost in a separate thread. Regards