Question

the mass of the train and its passengers is 250000kg the total kinetic energy is 18MJ calculate the velocity of the train as it enters​

Answer 1

Answer:

$\bigstar{\bold{Velocity=12\:m/s}}$

Explanation:

$\Large{\underline{\underline{\bf{Given:}}}}$

• Mass of the system (train + passengers)(m) = 250000 = 2.5 × 10⁵ kg
• Kinetic energy (K.E) = 18 MJ = 180 × 10⁵ J

$\Large{\underline{\underline{\bf{To\:Find:}}}}$

• Velocity of the train (v)

$\Large{\underline{\underline{\bf{Solution:}}}}$

→ K.E is given by the formula

  K.E = 1/2 × m × v²

→ Substituting the given datas we get the value of v

   180 × 10⁵ = 1/2 × 2.5 × 10⁵ × v²

   180 = 1/2 × 2.5 × v²

   v² = 144

   v = √144

$\boxed{\bold{Velocity=12\:m/s}}$

$\Large{\underline{\underline{\bf{Notes:}}}}$

→ The K.E of a body is the energy possessed by it due to virtue of its motion.

→ K.E = 1/2 × m × v²

→ K.E = p²/2m