maths2 - =-=-=-= = = = = =-=-= = 7 7 7 7 2 1 2 2 2 1 2 2...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
An electron makes two jumps into different energy levels before returning to the normal state. Its behaviour is modelled approximately by the function ( 29 2 t 2 1 te t v - = where t is measured in nanoseconds (ns) and v is speed measured in femtometres per nanosecond (fmns -1 ). (a) Sketch carefully and annotate the graph of v against t for –2 ≤ t ≤ 2 and –1 ≤ v ≤1. (b) What does dt ) t ( v 2 0 represent? It represents total distance travelled by electrons in time 0 to 2 ns. (c) Evaluate this integral using the substitution u = 1 – 2t 2 - - - - - - = -
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: =-=-=-= = = = = =-=-= = 7 7 7 7 2 1 2 2 2 1 2 2 4995 . ] 1 [ 2 1 | | 2 1 2 1 ) 2 ( now,-7 u 2 for t u for t du/(-2t) dt 2 2 1 , ) ( 2 2 fm e e du e t du te dt e t or tdt du t u ng substituti dt e t dt t v u u u t t (d) Hence, find the total distance travelled by the electron. fm 4995 . As calculated above (e) Sketch the graph of v(t) = ( 29 2 ) 2 t ( 2 1 e 2 t---for 0 ≤ t ≤ 4 and –1 ≤ v ≤ 1 (f) What is the total distance travelled by an electron with this speed over 4ns?...
View Full Document

This note was uploaded on 04/22/2011 for the course ECE 101 taught by Professor Yash during the Spring '11 term at Abraham Baldwin Agricultural College.

Ask a homework question - tutors are online