A. Space, time and motion

A.1 Kinematics

A.2 Forces and momentum

A.3 Work, energy and power

A.4 Rigid body mechanics

A.5 Galilean and special relativity

B. The particulate nature of matter

B.1 Thermal energy transfers

B.2 Greenhouse effect

B.3 Gas laws

B.4 Thermodynamics

B.5 Current and circuits

C. Wave behaviour

C.1 Simple harmonic motion

C.2 Wave model

C.3 Wave phenomena

C.4 Standing waves and resonance

C.5 Doppler effect

D. Fields

D.1 Gravitational fields

D.2 Electric and magnetic fields

D.3 Motion in electromagnetic fields

D.4 Induction

E. Nuclear and quantum physics

E.1 Structure of the atom

E.2 Quantum physics

E.3 Radioactive decay

E.4 Fission

E.5 Fusion and stars

S Skills in Physics

S1.1 Experimental techniques

S1.2 Technology

S1.3 Mathematics

S2.1 Exploring and designing

S2.2 Collecting and processing data

S2.3 Concluding and evaluating

IB Physics HL A.4 Rigid body mechanics Question Bank

[Maximum number: 2]

A box of mass 1.2 kg is lying at rest on a surface. The coefficient of static friction between the box and the surface is 0.36 and the coefficient of dynamic friction between the box and the surface is 0.28 .

(a)

The box is now standing up. The height of the box is 15.0 cm and its base is 6.0 cm . A person pushes the box with an increasing force F at the top until the box tips about the corner V without sliding, as shown.

[ 2 ]

(i)

Determine F.

[ 2 ]

[Maximum number: 1]

A wheel, initially at rest, rolls without slipping down an incline for 4.0 s . The final angular velocity of the wheel is $5 \pi \mathrm{rads}^{-1}$ .

How many revolutions did the wheel complete?

[Maximum number: 1]

A system of moment of inertia I rotates from rest about a given axis. The angular acceleration $\alpha$ of the system is constant.

What is the change in angular momentum when the system has made four complete rotations about the given axis?

$2 I \sqrt{2 \pi \alpha}$

$4 I \sqrt{\pi \alpha}$

$2 I \sqrt{2 \alpha}$

$4 I \sqrt{\alpha}$

[Maximum number: 1]

The graph shows how the angular acceleration $\alpha$ of a flywheel varies with torque $\tau$ applied to the flywheel.

What is the moment of inertia of the flywheel?

$0.20 \mathrm{~kg} \mathrm{~m}^{2}$

$5.0 \mathrm{~kg} \mathrm{~m}^{2}$

$40 \mathrm{~kg} \mathrm{~m}^{2}$

$80 \mathrm{~kg} \mathrm{~m}^{2}$

[Maximum number: 1]

An ice skater is spinning with their arms extended in a fixed position at a constant angular velocity. The ice skater then quickly pulls their arms closer to their body. Frictional effects are negligible.

Three statements are made about the ice skater's motion.

I. The angular momentum of the ice skater remains constant.
II. The rotational kinetic energy of the ice skater remains constant.
III. The net torque acting on the ice skater is zero.

Which of the statements are correct?

I and II only

I and III only

II and III only

I, II and III

[Maximum number: 1]

What is the unit of angular impulse?

$\mathrm{Nms}^{-1}$

Nms

[Maximum number: 1]

Two spheres, X and Y, are spinning with the same rotational kinetic energy. The moment of inertia of X is $I_{\mathrm{X}}$ and that of Y is $I_{\mathrm{Y}}$ .

What is $\frac{\text { angular momentum of } X}{\text { angular momentum of } Y}$ ?

$\sqrt{\frac{I_{\mathrm{X}}}{I_{\mathrm{Y}}}}$

$\sqrt{\frac{I_{\mathrm{Y}}}{I_{\mathrm{X}}}}$

$\frac{I_{\mathrm{X}}}{I_{\mathrm{Y}}}$

$\frac{I_{\mathrm{Y}}}{I_{\mathrm{X}}}$

[Maximum number: 1]

Two small spheres each of mass 10 kg are 8.0 m apart and connected by a rod of negligible mass. This system rotates about an axis halfway along the rod and at right angles to it.

What is the moment of inertia of the system?

$160 \mathrm{~kg} \mathrm{~m}^{2}$

$320 \mathrm{~kg} \mathrm{~m}^{2}$

$640 \mathrm{~kg} \mathrm{~m}^{2}$

$1280 \mathrm{~kg} \mathrm{~m}^{2}$

[Maximum number: 1]

A car of total mass M is travelling with a constant speed v. Each of the four wheels of the car has a mass m and a radius R and rolls without slipping.

The moment of inertia of each wheel is $I=\frac{1}{2} m R^{2}$ .
What is $\frac{\text { sum of the rotational kinetic energy of all four wheels }}{\text { translational kinetic energy of the car }} ?$

$\frac{m}{2 M}$

$\frac{m}{M}$

$\frac{2 m}{M}$

$\frac{4 m}{M}$

[Maximum number: 4]

Two blocks of mass m and 2 m are connected with a string that goes over a pulley of mass m.

When the blocks are released, the pulley turns about the axle as the blocks move. The string does not slip relative to the pulley. The radius of the pulley is r and its moment of inertia about the axle is $\frac{m r^{2}}{2}$ .

(a)

Show that the acceleration a of the blocks is given by $a=\frac{2 g}{7}$ .

[ 3 ]

(b)

Suggest whether the angular momentum of the pulley-blocks system is conserved.

[ 1 ]

0 selected

Question 1

Question 1(d)

Question 1(d)(i)

Question 6

Question 7

Question 7

Question 7

Question 7

Question 8

Question 8

Question 8

Question 6

Question 6(a)

Question 6(b)