Physics Answers

A stone has a weight of 5N in air and 4.5 N in water.What is the mass of the stone?

The viscous drag F experience by a spherical bob of radius (r) falling through a liquid is proportional to the radius of the bob, coefficient of viscosity, and terminal velocity (v). If the complant of propotionality is 6 pie, find the relationship between F, Radius, Viscosity and velocity

A stone of mass 20g falls from rest from a height 8m calculate it's k.e after falling from a distance of 5m

Write down the electronic configuration of Be (Z = 4) and determine the spectral terms 

for the ground state and first two excited states. Show transitions diagrammatically.

Given three vectors A = 24i + 33j, B = 55i - 12j and C = 2i + 43j

 (a) Find the magnitude of each vector.

 (b) Write an expression for the vector difference A - C.

 (c) Find the magnitude and direction of the vector difference A-B.

 (d) In a vector diagram show vector A + B, and A - B, and also show that your diagram agrees 

Construct your own theoretical model (including numerical calculations and physical processes) to continuously charge the earth if the currents (about 1800)

A) from atmosphere tend to flow towards it

(Else earth must get neutralised within about half an hour !)

A very very thin charged shell is set into spin (at some rate linearly increasing with time ). Calculate the electric field inside ? 

i) Describe a Foucault pendulum.

ii) Choose your latitude λ on Earth and write the equation of motion (EOM) for the pendulum.

iii) Use relevant octave script to plot the oscillations both in static and rotating coordinate systems. iv)Discuss when and how, in the actual experiment with pendulum in your lab, you would see the phenomena you see in part iii)

A person is riding on a flatcar traveling at a constant speed of 200 km/s (Fig.). He wishes to throw

a ball through a stationary hoop 90 km above the height of his hands in such a manner that the ball

will move horizontally as it passes through the hoop. He throws the ball with a speed of 250 m/s

with

respect to himself,

(a) How many time required after he releases the ball will it pass through the hoop?

(b) What must the vertical component of the initial velocity of the ball?

(c) At what horizontal distance in front of the hoop must he release the ball?

(d) When the ball leaves the man's hands, what is the direction of its velocity relative to the

frame of reference of the flatcar? Relative to the frame of reference of an observer standing

on the ground?

90 km

V

V

X

v = 200 km/s

A system of four(4) free particles each has a mass m_i and initial position r_i and initial velocity v_i .

i) Describe your own four-particle system in detail.

ii) Determine the position R_cm and velocity V_cm of the centre of mass of the system.

iii) Determine the total linear momentum P_tot and the linear momentum P_cm of the centre of mass of the system.

iv) Determine the total angular momentum L_tot and the linear momentum P_cm of the centre of mass of the system.

v) Discuss briefly about your answers in part ii), iii), iv)