Question

Since there isn't cnough fuel to get your ship off of the planct, Capt. Reynolds decides to repair the alien ship and takc it, along with a small crew that includes the captain, Commander Martin McFly, and you, off the planct on a mission to find help. After leaving the planet, your ship is traveling through space when you encounter a 500 kg asteroid hurtling toward the ship at 4 km/s. There isn't cnough timc to avoid the asteroid, so thc Captain orders you to fire photon torpedocs at it to bring it to a stop. Each torpedo has the same mass, 20 kg, travels at 10 km/s, and becomes completely embedded in the asteroid after they hit. How many torpedoes will it take to stop the astcroid?

Answer 1

Momentum of asteroid = 500 kg × 4 km/s

= 2000 kg.km/s

Momentum of each torpedo= 20 kg ×10 km/s

= 200 kg.km/s

To cancel of momentum of asteroid a total of (2000÷200) = 10 torpedoes will be required.