Mechanics | Relativity Answers

Copper (cu) has crystal structure Atomic mass of Cu is 63.55 gmol^-1 and radius of a copper atom is 0.128 nm, mean speed of conduction electrons in Cu is 1.5 ×10^6 ms^-1 and frequency of vibration of the Cu atoms at 27 °C is 4×10^12 S^-1 Nordheim’s

Coefficient of Au in Cu is 5500

Ω −m

Caculate (a) the atomic density of copper (b) Estimate the drift mobility of electronics in cu (c) find the resistivity of pure copper cu (d) find the resistivity of copper if 1 at % of Au is mixed in Cu

A cube of volume 1 cubic metres and specific gravity 2 is very slowly being lowered in to a lake with help of a massless string tied to one of its vertices A (i.e., body diagonal AB is perpendicular to surface of water).

Initially, the other opposite vertex B is just touching the surface of water and finally, vertex A is just beneath the surface of water. (Ignore change in KE of water). (g= 10ms2).

Find
(a) Work done by gravity on cube.
(b) Work done by gravity on water
(c) Work done by gravity on water + cube system.
(d) Work done by tension on cube.

4. A man applied a force of 50N to the nutcracker. The nutcracker applies a force of 750N to the pecan. What is the mechanical advantage?

A football coach walks 12 meters westward, then 16 meters eastward, then 22 meters westward, and finally 6 meters eastward.
For this motion, what is the distance moved?
What is the magnitude and direction of the displacement?

The distance between the sixth and the eleventh floors of a building is 30.0m. The combined mass of the elevator and its contents is 1350 kg. a) find the gravitational potential energy of the elevator when it stops at the eighth floor, relative to the sixth floor.

Source https://www.physicsforums.com/threads/finding-gravitational-potential-energy.310390/

An engine block is supported by a rope hoist attached to an overhead beam.when the block is pulled to one side by a horizontal force exerted by another rope,the tension in the rope hoist

The slotted link mechanism shown in Figure 4 provides slow forward quick-return motion to the cutting tool of a shaping machine. The slotted link AC is 1 m in length and the connecting link CD is 150 mm in length. The sliding block, B, is set at a radius of 200 mm from the centre O of the driving wheel. Determine the angular velocity of the slotted link and the velocity of the cutting tool at the instant shown.