Thermodynamics — Physics STD 11 Science — Question

A metal block of density 6000kg m^-3 and mass 1.2kg is suspended through a spring of spring constant 200N m^-1. The spring-block system is dipped in water kept in a vessel. The water has a mass of 260g and the block is at a height 40cm above the bottom of the vessel. If the support to the spring is broken, what will be the rise in the temperature of the water. Specific heat capacity of the block is 250Jkg^-1 K^-1 and that of water is 4200Jkg^-1 K^-1. Heat capacities of the vessel and the spring are negligible.

The gravitational force between a hollow spherical shell (of radius R and uniform density) and a point mass is F. Show the nature of F vs r graph where r is the distance of the point from the centre of the hollow spherical shell of uniform density.

A heavy point mass tied to the end of string is whirled in a horizontal circle of radius 20cm with a constant angular speed. What is angular speed if the centripetal acceleration is 980cm/ s^-2?

What is the apparent weight of a man of mass 60kg who is standing on a lift which is moving up with a uniform speed? (g = 10ms^-2)

Do all solids expand on heating? Name the solid that contracts on heating.

Fig. depicts four x-t plots for linear motion of a particle. Which of the plots represent periodic motion? What is the period of motion (in case of periodic motion)?

A mass of 2kg is attached to the spring of spring constant 50Nm^–1 . The block is pulled to a distance of 5cm from its equilibrium position at x = 0 on a horizontal frictionless surface from rest at t = 0. Write the expression for its displacement at anytime t.

Why is the head of screw made wide?

The density of a rod AB continuously increases from A to B. Is it easier to set it in rotation by clamping it at A and applying a perpendicular force at B or by clamping it at B and applying the force at A?