Moments and turning effectsIB MYP Physics: Flashcards

Exam questions on Moments and turning effects

1. A mechanic in São Paulo uses a spanner 0.25 m long to loosen a wheel nut. She pushes at right angles to the end of the spanner with a force of 80 N, but the nut does not turn.
   She slides a long pipe over the spanner so that she can push 0.50 m from the nut with the same force. Explain why this helps her to turn the nut.2 marks
2. Two children sit on a see-saw that has its pivot at the centre. Child P weighs 300 N and sits 2.0 m from the pivot on the left. Child Q weighs 400 N and sits on the right. The see-saw is balanced horizontally.
   Child Q now moves so that she sits 2.0 m from the pivot. Explain what happens to the see-saw.2 marks
3. A student investigates balancing a uniform metre rule that is pivoted at its centre, so the weight of the rule itself has no turning effect. A 4.0 N load is hung 0.30 m to the left of the pivot. She hangs different weights on the right and moves each one until the rule balances. A 2.0 N weight balanced at 0.60 m from the pivot, a 3.0 N weight at 0.40 m and a 6.0 N weight at 0.20 m.
   State the independent variable, the dependent variable and one control variable in this investigation.3 marks