Date | May 2021 | Marks available | 2 | Reference code | 21M.2.SL.TZ1.2 |
Level | Standard level | Paper | Paper 2 | Time zone | 1 |
Command term | Determine | Question number | 2 | Adapted from | N/A |
Question
A planet is in a circular orbit around a star. The speed of the planet is constant.
Explain why a centripetal force is needed for the planet to be in a circular orbit.
State the nature of this centripetal force.
Determine the gravitational field of the planet.
The following data are given:
Mass of planet kg
Radius of the planet m.
Markscheme
«circular motion» involves a changing velocity ✓
«Tangential velocity» is «always» perpendicular to centripetal force/acceleration ✓
there must be a force/acceleration towards centre/star ✓
without a centripetal force the planet will move in a straight line ✓
gravitational force/force of gravity ✓
use of ✓
6.4 «Nkg−1 or ms−2» ✓