11.1 Measurements-01

Find the dimensions of

a.      Power

b.     Force

c.      Permittivity of free space

12.5. Elasticity - 1

A wire of length 2 m and area of cross section 10^-4 m² is stretched by a load 102 kg. The wire will stretched by 0.1 cm

Calculate

a.     Longitudinal stress

b.     Longitudinal strain

c.      Young’s modulus of wire

11.2. Scalars and Vectors – ( 1 )

Two forces f₁ and f₂ of magnitude 5N each inclined each other at 60^o, act on a body. Find the resultant force acting on body.

12.4. Oscillations - 1

A particle is executing S.H.M. of amplitude 5 cm and period of 2 sec. Find the speed of particle at a point where its acceleration is half of its maximum value.

Calculate the angular velocity of disc

A circular disc of mass 10 kg and radius 0.2 m is set in to rotation about an axis passing through its centre and perpendicular to its plane by applying torque 10 Nm. Calculate the angular velocity of disc that it will attain at the end of 6 sec from the rest.

Solution 

2.1 Show that the critical velocity of a body revolving in a circular orbit very closed to the surface of planet of radius ‘ R ’ and mean density ρ is Vc = 2 R √ [ (G ρ π ) / 3 ]

                      

Solution- 

1.1 Calculate the angular velocity and linear velocity of a tip of minute hand of length 10 cm.

1.1         Calculate the angular velocity and linear velocity of a tip of minute hand of length 10 cm.