A train is moving with a velocity of 100 km/hr. Car A is traveling with velocity 100km/hr w.r.t. train in the opposite direction. Car B is traveling at the rate of 100 km/hr on the ground alongside the train. A man X is sitting inside the train and a man Y is standing outside the train and watching the entire episode. With respect to who is the car A at rest?
A train is moving with a velocity of 100 km/hr. Car A is traveling with velocity 100km/hr w.r.t. train in the opposite direction. Car B is traveling at the rate of 100 km/hr on the ground alongside the train. A man X is sitting inside the train and a man Y is standing outside the train and watching the entire episode. With respect to who is the car A at rest?
The correct option is D Man Y
Lets check all options Car A in moving 100 km/hr w.r.t train
= - 100 so the car can't be at rest w.r.t. train.
= - 100 =VA−Vt
=VA−100
As velocity of train = + 100 km/hr
⇒ - 100 = VA−100
VA=0
So velocity of A w.r.t ground = 0
Option B Man X is in train so his velocity as same as that of the train VX=100m/s.
= 0 - 100 = - 100 = - 100 and not 0
Option C Car B
Velocity of Car B = - 100 km/hr
= VA−VB = 0 - 100 = + 100
So A is not at rest when seen from B
Option D Man Y
Vy=0 w.r.t. ground as he is just standing
So car A is at rest as seen from Man Y
Man Y
Lets check all options Car A in moving 100 km/hr w.r.t train
= - 100 so the car can't be at rest w.r.t. train.
= - 100 =VA−Vt
=VA−100
As velocity of train = + 100 km/hr
⇒ - 100 = VA−100
VA=0
So velocity of A w.r.t ground = 0
Option B Man X is in train so his velocity as same as that of the train VX=100m/s.
= 0 - 100 = - 100 = - 100 and not 0
Option C Car B
Velocity of Car B = - 100 km/hr
= VA−VB = 0 - 100 = + 100
So A is not at rest when seen from B
Option D Man Y
Vy=0 w.r.t. ground as he is just standing
So car A is at rest as seen from Man Y
