Saturday, March 30, 2013

Invisible Jacket Created By Scientist

This innovation is found by Andrea and being published by “New Journal of Physics” 26 March Edition. Invisible jacket like in Harry Potter, now have been created by Muggle scientist, even this jacket can only work on micro wave invisible light.

Nevertheless, it remains a great creation. The physicists are making a new robe, said it was a step forward to realize the invisibility cloak that can hide one in the afternoon light. This creation is made from metascreen material, copper tape material attached to a flexible polycarbonate films. Pieces of copper was only 66 micrometers thick (66 millionth of a meter), while the polycarbonate films only 100 micrometers thick, and the two combined in a diagonal pattern of the net.

Invisible jacket can work because deflect the rays around an object so that the light does not spread or bounce, a technique that relies metamaterials (artificial material, not the material naturally) large. The new robes using a technique called sheath coat to prevent light waves reflected from the object that is covered, so that no light can bounce into the eyes of those who view the object.

Thursday, August 2, 2012

Movement Problem

Solve these Physical Problems:

1. A good have 2 kg weight is moving with constant speed, suddenly collide sand bag and get force f with time function as on the picture below.

 Speed changes on the first 4 second is ….

(a) 11.6 m/s
(b) 10.6 m/s
(c) 9.6 m/s
(d) 8.6 m/s
(e) 7.6 m/s

2. Two good each have simple dynamic moving with each formula as follows:

 y1 = 8 sin 100t, y2 = 6 sin (100t – π/2), where x and y in cm while t in second, the magnitude of amplitude superposition of both vibration is ……

(a) 14 cm
(b) 10 cm
(c) 8 cm
(d) 6 cm
(e) 2 cm