Measuring the mass of

an astronaut

TP

TP

Doppler Effect

(red shift et bleu shift)

rotation period of Mercury

TPMeasure of the differential rotation

of the Sun by observing solar spots

Δ

TPRemote

sensing

The mass of a black holeTP

Elliptic motion (a)

Period (T)

3°Kepler law

Reference star

TP

http://eoedu.belspo.be/fr/profs/index.htm

Huriccane speed

Boyle et Mariotte

TP

freefall study

(T48) Matteo Siccardi: Apllet Geogebra

Screencasting

Measuring the mass of an astronaut

Why measuring the mass?

• For the look ?

Why measuring the mass?

• osteoporosis ?

zero gravity

weightless

environment

Why measuring the mass?

• For EVA (Extra Vehicular Activity)?

spacesuit

Problem?

zero gravity

Harmonic motion

harmonic oscillators

A suspended from a spring

(translation oscillator) object

can oscillate on either side of

an equilibrium position.

0

- Max

+ Max

All periodic oscillating movements "can be assimilated" to the projection on an axis of

a turning point X at constant speed on a "trigonometric" circle of radius R = Max.

0

- Max

+ Max

yy

: angular speed (rad/s)

t: time (s)

: angle

= .t

y=Y.sin( )

Where:

Y: amplitude

: pulsation

.t: phase

y: gives the position, the value of an electric field, pressure, ....

It is possible to calculate the speed at which the position varies, the electric field or

pressure, ... during a time interval t.

We can also calculate how the speed varies during time interval t.

To get an accurate speed and instant acceleration, just use a very small t that the limit

tends to zero, or just take the derivative with respect to time.

The speed

L’accélération

Dynamics of the harmonic oscillator

remark:

The time (and therefore frequency) is independent of the amplitude (A)

Spring constant

Force sensor