Question 22N.2.SL.TZ0.b
| Date | November 2022 | Marks available | [Maximum mark: 3] | Reference code | 22N.2.SL.TZ0.b |
| Level | SL | Paper | 2 | Time zone | TZ0 |
| Command term | Explain | Question number | b | Adapted from | N/A |
Explain why the magnitude of the force exerted on the mass by the rod is not constant.
[3]
ALTERNATIVE 1
the net/centripetal force has constant magnitude ✓
the direction of the net/centripetal force constantly changes ✓
this is achieved by vector-adding weight and the force from the rod
OR
the force from the rod is vector difference of the centripetal force and weight ✓
ALTERNATIVE 2
at the top Frod = Fc − W ✓
at the bottom, Frod = Fc + W ✓
net F/Fc is constant so the force from the rod is different «hence is changing» ✓
Accept reference to centripetal or net force indistinctly.
Allow reference to centripetal acceleration.
Many got into a bit of a mess with this one and it was quite difficult to interpret some of the answers. If they started out with the net/centripetal force being constant, then it was often easy to follow the reasoning. Starting with force on the rod varying often led to confusion. Quite a few did not pick up on the constant speed vertical circle so there were complicated energy/speed arguments to pick through.
