Question 18N.2.SL.TZ0.c.ii
| Date | November 2018 | Marks available | [Maximum mark: 2] | Reference code | 18N.2.SL.TZ0.c.ii |
| Level | SL | Paper | 2 | Time zone | TZ0 |
| Command term | Explain | Question number | c.ii | Adapted from | N/A |
Ion-thrust engines can power spacecraft. In this type of engine, ions are created in a chamber and expelled from the spacecraft. The spacecraft is in outer space when the propulsion system is turned on. The spacecraft starts from rest.
The mass of ions ejected each second is 6.6 × 10–6 kg and the speed of each ion is 5.2 × 104 m s–1. The initial total mass of the spacecraft and its fuel is 740 kg. Assume that the ions travel away from the spacecraft parallel to its direction of motion.
In practice, the ions leave the spacecraft at a range of angles as shown.
Explain what effect, if any, this spreading of the ions has on the acceleration of the spacecraft.
[2]
the forces between the ions do not affect the force on the spacecraft. ✔
there is no effect on the acceleration of the spacecraft. ✔
