The supernova expansion In a supernova explosion, initially the supernova expands freely. Then the supernova enters a new stage when in the existent gas around the star, shock waves push out the matter. This lasts for $10^4$ years. The model that describes the shock waves stage is named the Taylor-Sedov model. Let us say that

## Acoustic Impedance

Pipe Acoustic Impedance Let us suppose that we want to send an acoustic wave from left towards right through a series of connected pipes having different areas. What is the acoustic impedance of each pipe? a) For two pipes connected in series first having an area of 4A and the second an area of A,

## Falling Electron (on Nucleus)

The falling electron Using the classic EM framework, a falling electron $e^-$ (a negative charge) emits energy/time as $W= (2/3)*(a^2e^2/c^3)$ (erg/s) where $a$ is the acceleration of the falling electron in its circular path around the nucleus and $c$ is light’s speed. If initially the radius of the atom is $R= 1 A=10^{-10} m$ please

## Motorola M68000 Assembler

MOVE and CLR 8. If the value stored in the data register of Motorola M68000 D0 = \$ABCD1234, what is the data found in register D0 at the end of each line. a) MOVE #5, D0 D0=\$00000005 b) MOVE #10, D0 D0=\$0000000A c) MOVE #-1, D0 D0=\$0000FFFF d) MOVE #\$1234, D0 D0=\$00001234 e) MOVE #%1011,

## Velocity versus Time

Velocity as function of time You are given the dependence of velocity as function of time from the figure. Please find the position as function of time from the given graph, if the initial condition is $x(0)=0m$. Also what is the position at 3s, 8s, and 10 s and the times when the slope of

## Planet Distance

Question 1 A classic radiotelecope detects a planet’s hydrogen emitted waves of $\lambda=21 cm$. If the signal emitted by a planet has a wavelength that is 0.28 cm longer than the standard 21 cm wavelength what is the distance to this planet? (Instead of planet there could be a galaxy for example) The redshift is

## Right shift and left shift

In general dividing by 2 is equivalent to right shifting with 1. Also left shifting with 1 is equivalent to multiplication with 2. (a) Is a right shift equivalent to a division exactly by 2? For example shift 0x9A with 1, 2 and 3 and show what values you obtain. (b) Is sifthing towards right