Torque Angular Momentum and Equilibrium
Important Easy Notes of Physics of Chapter No.5:Torque Angular Momentum and Equilibrium written by Professor Mr. M. Talha Suib. These notes are very helpful in the preparation of Physics for students of the 11th class and these are according to the paper patterns of all Sindh Book Boards.
Summary and Contents:
Topics which are discussed in the notes are given below:
- Very Important Multiple Choice Questions (MCQs) with Answers of the Chapter No.5:Torque Angular Momentum and Equilibrium in Physics Class 11 Sindh Book Boards.
- Definition of Torque with explanation and Magnitude
- In Rectangular Component Form
- Definition of Couple with explanation and Magnitude
- Definition of Centre of Mass with explanation and Magnitude
- Centre Of Mas And Centre Of Gravity and Determination Of Centre Of Mass
- Definition of equilibrium
- Definition of a static equilibrium
- Definition of dynamic equilibrium
- Conditions of equilibrium: (a) First condition of equilibrium (translation equilibrium) (b) Second Condition Of Equilibrium:(rotational Equilibrium)
- State and Explain First condition of equilibrium (translation equilibrium)
- State and Explain Second Condition Of Equilibrium:(rotational Equilibrium)
- Define and explain Angular Momentum with dimension and unit
- State and explain law of conservation of angular momentum
- Locate the centre of mass of a system of particles each of mass βmβ, arranged to correspond in position
to the six corners of a regular (planar) hexagon.
- Find the position of centre of mass of five equal-mass particles located at the five corners of a square- based right pyramid with sides of length βπβ and altitude βhβ.
- The mass of the sun is 329.390 times the earthβs mass and the mean distance from the centre of the sun
to the centre of the earth is 1.496x108 km. Treating the earth and sun as particles with each mass
concentrated at the respective geometric centre, how far from the centre of the sun is the C.M (centre of
mass) of the earth-sun system? Compare this distance with the mean radius of the sun (6.9960x105 km).
- A particle of mass 4 kg moves along the x-axis with a velocity v = 15t m/s, where t = 0 is the instant
that the particle is at the origin.
(a) At t= 2 s , what is the angular momentum of particle about a point P located on +ve y axis 6 m from the
origin?
(b) What torque about P acts on the particle?
- A particle of mass βmβ is located at the vector position r and has a linear momentum vector p. The
vector r and p are non zero. If the particle moves only in the x, y plane, prove that π³π = π³π = π πππ
π³π β π
- A light rigid rod 1m in length rotates in the xy-plane about a pivot through the rodβs centre. Two
particles of mass 2kg and 3kg are connected to its ends. Determined the angular momentum of the system
about the origin at the instant the speed of each particle is 5m/s.
- A uniform beam of mass βMβ supports two masses m1 and m2. If the knife edge of the support is under
the beamβs centre of gravity and m1 is at a distance βdβ from the centre, determine the position of m2 such
that the system is balanced.
- A uniform ladder of length π and weight W = 50 N rests against a smooth vertical wall. If the coefficient
of friction between the ladder and the ground is 0.40, find the minimum angle ΞΈmin such that the ladder may
not slip.
- A ladder with a uniform density and a mass βmβ rests against a frictionless vertical wall at an angle of
60o . The lower end rests on a flat surface where the coefficient of friction (static) is 0.40. A student with a
mass (M = 2m) attempts to climb the ladder. What fraction of the length βLβ of the ladder will the student
have reached when the ladder begins to slip?
- A particle of mass 0.3 kg moves in the xy-plane. At the instant its coordinates are (2, 4)m, its velocity
is (3i + 4j)m/s. At this instant determine the angular momentum of the particle relative to the origin.
- A uniform horizontal beam of length 8m and weighing 200N is pivoted at the wall with its far end
supported by a cable that makes an angle of 53o with the horizontal. If a person weighing 600N stands 2m
from the wall, find the tension and the reaction force at the pivot.
- A particle of mass 500 gm rotates in a circular orbit of radius 25 cm at a constant rate of 1.5
revolutions per second. Find the angular momentum with respect to centre of the orbit .
- A particle of mass 0.5 kg moves along xy-plane. At that instant, the coordinates are (3, 4)m and its
velocity is (4i +5j) m/sec. Determine the angular momentum relative to origin at that time.