A wagon of mass 2000 kg is separated from a train travelling at 9 km/h and comes to the rest in 2 minutes. What is the resistance between the wheels of the wagon and the track?

Question

A wagon of mass 2000 kg is separated from a train travelling at 9 km/h and comes to the rest in 2 minutes. What is the resistance between the wheels of the wagon and the track? (A) 42 N (B) 41.7 N (C) 45 N (D) 47 N

Tardigrade Admin · Accepted Answer

u =9 × (5/18)=2.5 m / s , v =0 t =60 sec Resistance = Force =(m(v-u)/t) =(2000(0-2.5)/2 × 60) Resistance =-41.7 N (-ve sign shows that resistance occurs in opposite direction)

Q. A wagon of mass $2000 k g$ is separated from a train travelling at $9 km / h$ and comes to the rest in 2 minutes. What is the resistance between the wheels of the wagon and the track?

42 N

41.7 N

45 N

47 N

$u = 9 \times \frac{5}{18} = 2.5 m / s, v = 0 t = 60 sec$
Resistance $=$ Force $= \frac{m ( v - u )}{t}$
$= \frac{2000 ( 0 - 2.5 )}{2 \times 60}$
Resistance $= - 41.7 N$
(-ve sign shows that resistance occurs in opposite direction)

Q. A wagon of mass 2000kg is separated from a train travelling at 9km/h and comes to the rest in 2 minutes. What is the resistance between the wheels of the wagon and the track?