Molecular Physics | Thermodynamics Answers

A ball is thrown 125 meters upward and then falls the same distance back on earth. Neglecting air resistance, its total time in the air is

A ball of mass 0.150 kg is dropped from rest froma height of 1.25m .it rebounds from the floor to reach a height of 0.960m .what impulse was given to the ball by floor?

Four sled dogs are pulling a 1000kg load. Sled dog A is pulling the load at 20N, 10 degrees north of east. Sled dog B is pulling the load at 55N, 70 degrees north of east. Sled dog C is pulling the load at 45N, 33 degrees north of west, while sled dog D exerts 30N at a direction of 80 degrees south of west. What is the resultant force acting on the load?

A gas with a velocity of 300 m/s is flowing through a horizontal pipe at a

section where pressure is 78 kN/m2 absolute and temperature 40°C. The pipe changes in diam￾eter and at this section, the pressure is 117 kN/m2 absolute. Find the velocity of the gas at this

section if the flow of the gas is adiabatic. Take R = 287 J/kg K and γ = 1.4

. Find the sonic velocity for the following fluids :

(i) Crude oil of specific gravity 0.8 and bulk modulus 1.5 GN/m2 ;

(ii) Mercury having a bulk modulus of 27 GN/m2.

. A supersonic aircraft flies at an altitude of 1.8 km where temperature is

4°C. Determine the speed of the aircraft if its sound is heard 4 seconds after its passage over the

head of an observer. Take R = 287 J/kg K and γ = 1.4

A projectile is travelling in air having pressure and temperature as

88.3 kN/m2 and – 2°C. If the Mach angle is 40°, find the velocity of the projectile. Take γ = 1.4 and

R = 287 J/kg K.

An aeroplane is flying at 1000 km/h through still air having a pressure of

78.5 kN/m2 (abs.) and temperature – 8°C. Calculate on the stagnation point on the nose of the

plane :

(i) Stagnation pressure,

(ii) Stagnation temperature, and

(iii) Stagnation density.

Take for air : R = 287 J/kg K and γ = 1.4

A heat pump heats a house in the winter and then reverses to

cool it in the summer. The interior

temperature should be 20°C in the winter and 25°C in the summer. Heat transfer th

rough the

walls and ceilings is

estimated to be 2400 kJ per hour per degree temperature difference

between the inside and outside. (a) If t

he winter outside temperature is 0°C, what is the

minimum power required to drive the heat pump? (b) For the same power as in part (a), what

is the maximum outside summer temperature for which the house can be maintained at 25°C?

Show the schematic diagram

s of the systems.