Question

bus starts from rest and moving with a velocity of 72 kilometre per hour in 20 minutes calculate the acceleration and force if the mass of bus is 2000 kg​

Answer 1

Given,

Mass of car, M=2000kg

Velocity, V=72×

18

5

=20ms

−1

Apply kinematic equation of motion

v

2

−u

2

=2as

0−20

2

=2a×20

a=−10ms

−2

Breaking force, F=ma=2000×10=20 kN

Apply first kinematic equation

v=u+at

t=

a

v−u

=

−10

0−20

=2 sec

Breaking force is 20 kNand time is 2sec.

Answer 2

Answer:

Given,

Initial Velocity (u) = 0 m/s

Final Velocity (v) = 72 km/hr

= (72*5/18) m/s

= 20 m/s

Time (t) = 20 mins

= (20*60) seconds

= 1200 seconds

v = u+at

= 20 = 0+(1200a)

= 20 = 1200a

= 0.01666 m/s²

Force = Mass*Acceleration

Given that Mass is 2000 kg,

= Force = 2000*0.01666

= Force = 33.32 N

I hope this helps.