IB Physics HL A.4 Rigid body mechanics questions

Exam-style multiple choice and written questions with full markschemes. Check multiple choice answers straight away, or type, photograph or draw a written answer and get it marked.

Type
Multiple choiceWritten
Difficulty
EasyMediumHard

Question 1

Paper 2Medium4 marks

A horizontal turntable rotates about a fixed vertical axis. Its moment of inertia, excluding two identical small masses, is 0.40 kg m20.40\ \mathrm{kg\,m^2} The masses are moved inward by radial forces through the axis. The bearing exerts negligible torque about the vertical axis. Treat the masses as point particles and the arms as having negligible mass.

Figure 1 shows the initial and final positions of the masses.

initialafter inward motionvertical axisOvertical axisO0.50 kg0.50 kg0.50 kg0.50 kgri=0.60 mrf=0.30 mωi=2.0 rad s−1
(a)

Determine the angular speed of the turntable after the masses have moved inward.

[3]
(b)

Explain why the angular momentum of the turntable–masses system about the vertical axis remains constant while the masses move.

[1]

The best questions are still waiting

Unlock every question in this topic, then type, photograph or draw your answer and have it marked against the markscheme. Find out where you are dropping marks.

Unlock all questionsCompare Student and Student Plus