Properties of matter questions | form five Physics

Use a sketch graph to show how extension of the wire varies with the applied force and mark the elastic limit and yield point on it. Explain how the magnitude of the Young`s modulus is obtained from the graph.

A block of metal weighing 20N with a volume of 8x10^-4m³ is completely immersed in oil of density 700kgm^-3 then attached to one end of a vertical wire of length 4.0 m and diameter of 0.6mm whose other end is fixed. If the length of the wire is increased by 1.0 mm, find the

1. Young`s modulus of the wire
2. Energy stored in the wire

A rubber cord  of a Y-shaped object has a cross sectional area of 4x10^-6m² and relaxation length of 100mm. If the armsof the catapult are 70mm apart, calculate the

1. tension in the rubber
2. force required to stretch it when the rubber cord is pulled back until its length doubles.

Briefly give comments on the following observations

1. Polyatomic and diatomic gases have larger molar heat capacity than monatomic gases.
2. Cubical container is used for the derivation of pressure of an ideal gas.

1. What is meant by a gas constant?.
2. Helium gas occupies a volume of 4x10^-2m³ at a pressure of 2x10⁵ Pa and temperature of 300K. Calculate the mass of helium and the r.m.s speed of its molecules.

When a gas expand adiabatically it does work on its surroundings although there is no heat input to the gas. Explain where this energy is coming from.

An ideal gas at 17^oC and 750 mmHg is compressed isothermally until its volume is reached to of its initial value. If then allowed to expand adiabatically to a volume of 20% greater than its original value, calculate the final temperature and pressure of the gas.