Mechanics | Relativity Answers

Which of the following is a set of vectors?
velocity and volume
weight and displacement
density and distance
mass and force

Why is it easier to open the lid of a container with a spoon than a coin?

define and explain free and forced oscillations

1. A rod of length l and radius r is joined to a rod of length l/2 and radius r/2 of same material. The free end of small rod is fixed to a rigid base and the free end of larger rod is given a twist of A degrees. The twist angle at the joint will be (ans-8A/9)

2.A uniform wire of length l and radius r is twisted by angle A. if modulus of rigidity of wire is B then elastic potential energy stored in wire is?(ans-pie*B*r^4*A^2/4l)

3.Two wires A and B are of same length and of same material having radii r1 and r2 respectively. Their one end is fixed with a rigid support and at the other end equal twisting couple is applied. Then ratio of the angle of twist at the end of A and the angle of twist at the end B will be? ans-r1^2/r2^2

Define and explain forced and damped Oscillation Mathematical analysis.

Define and explain physical pendulum.

Let a copper rod of mass m rest on two horizontal rails that are L meters apart and carry a current of I amperes from one rail to another. Let the coefficient of static friction between the rod and the rails be u.
What is the (1)magnitude and (2) angle (with respect to the vertical) of the smallest magnetic field that puts the rod on verge of sliding ?

Does the velocity of the particles of fluid at rest changes in downward direction due to gravitational force? If so, why does it change? For finding pressure for fluid at rest the formula is p=hdg. Why don't we take the average of two accelerations, the acceleration of particles of fluid instead of acceleration due to gravity?

A stone is dropped from the top of a tower 400 m high and at the same time another stone is projected upward vertically from the ground with velocity of 100 m/sec. Find when and where the two stone will meet?

why to empty h meter deep fulfilled well, the height is used h/2?

why to raise water from a h meter deep fulfilled well, the height is used h?

why to empty the half of a fulfilled well which is h meter deep, the height is used h/4?

why to raise water from a h meter deep well which has water level at h/4 ,the height is used 3h/4?

what is the main concept? please xplain