Mechanics | Relativity Answers

A mass of 10 kg hangs from one end of a 1 m long light rod that is pivoted 0.3 m from that end.
(a) what force must be applied at the 0.6 m mark to balance the rod?
(b) if force of 20N is hung from the 0.5 m mark what force must be hung from the 1 m mark to balance the rod?

A bullet of mass 0.02kg is moving with a speed 10m/s. It can penetrate 10 cm if a given target before coming to rest. If the same target were only 6 cm thick, what will be the speed and kinetic energy of the bullet, when it comes out.

A bead of mass m is attached to one end of a spring of natural length 3 R and
spring constant k = (31)+mgR . The other end of the spring is fixed at point A on a
smooth fixed vertical ring of radius R as shown in the figure. What is the normal ?

A man gets 100 k.cal of heat energy by eating a piece of bread His efficiency is 28 percent and mass is 60 kg . How high can he rise after eating the bread

the position of a 0.30 kg object attached to a spring is described by x=(0.25 m)cos(0.4π t).
find:

A.) the amplitude of the motion
B.) the spring constant
C.)the position at t= 0.30s
D.) the object speed at t=0.30s

a 60 kg woman stands at the rim of a horizontal turntable having a moment of inertia of 500 kg.m^2 and a radius of 2.00 m. the turntable is initially at rest and is free to rotate about a frictionless, vertical axle through its center. the woman then starts walking around the rim clockwise (as viewed from above the system) at a constant speed of 1.50 m/s relative to earth.
A.) in what direction and with what angular speed does the turntable rotates?
B.)how much work does the woman do to set herself and the turntable in motion?

What is the lift (in newtons) due to Bernoulli's principle on a wing of area 86 m^2 if the air passes over the top and bottom surfaces at speeds of 340 m/s and 290 m/s respectively?

There is no mass, no charge in space or vacuum then how electric and magnetic fields are varying in space?

A proton moving with a speed of 1.0x10e7 m/sec passes through a 0.020 cm thick sheet of paper and emerges with a speed of 2.0x10e6 m/sec. Assuming uniform deceleration, find retardation and time taken to pass through the paper?

An object is traveling with a constant acceleration of 10 meter per second square how much distance will it travel in 3rd second of its journey