MYTUTOR SUBJECT ANSWERS

210 views

Explain the workings of a mass spectrometer

Charged particles are fired into a magnetic field (perpendicular to the motion of the particles). Using Fleming’s left hand rule, a magnetic force acts centripetally – such that the charged particles exhibit circular motion.

By equating the magnetic force acting on each charge, with the equation for centripetal force, we have:

Bqv=mv2/r    (1)

Where B is the magnetic field strength

            q is the charge of each particle

            m is the mass of each particle

            r is the radius of curvature of each particle (i.e. the radius of circular motion)

            v is the speed of each particle.

Rearranging equation (1) for m, we have:

m=Bqr/v          (2)

Equation (2) allows us to calculate the mass of ionised atoms, with a charge q related to the number of electrons each ion has gained/lost, assuming we can measure the radius and velocity of each particle. In practice, we would fire the ions through a florescent gas, so their circular motion becomes visible. The speed at which ions enter the magnetic field, v, can be adjusted using an electric field to accelerate the ions into the magnetic field. 

Dan S. GCSE Physics tutor, A Level Physics tutor, GCSE Maths tutor, A...

8 months ago

Answered by Dan, an A Level Physics tutor with MyTutor


Still stuck? Get one-to-one help from a personally interviewed subject specialist

57 SUBJECT SPECIALISTS

£20 /hr

Peter H.

Degree: Mathematics (Bachelors) - Durham University

Subjects offered: Physics, Maths+ 2 more

Physics
Maths
Further Mathematics
.STEP.

“About me: I am a Mathematics student at Durham University, and I am currently in my 3rd year. I would very much like to give assistance and help students of all abilities to reach the goals they aspire to in Maths and Physics, whether...”

MyTutor guarantee

£20 /hr

Tate C.

Degree: Mechanical Engineering (Masters) - Bath University

Subjects offered: Physics, Maths+ 1 more

Physics
Maths
Chemistry

“My name is Tate. I am, immensely interested in everything Physics simply because I really see no subject offering the same level of awe inpsiring information that consistently motivates me to go and learn more. I love it so much Ieven...”

£20 /hr

Ewan H.

Degree: Aerospace Engineering (Masters) - Bristol University

Subjects offered: Physics, Maths+ 1 more

Physics
Maths
-Personal Statements-

“About me:I am currently a first year at Bristol University studying Aerospace Engineering. Given my degree, my interests have always been interested in thesciences and maths.I have always been involved in various tutoring groups, m...”

About the author

Dan S.

Currently unavailable: for regular students

Degree: Physics (Masters) - Exeter University

Subjects offered: Physics, Maths

Physics
Maths

“I`m a second year Physics student at the University of Exeter, with a passion for Physics and Mathematics. I`m happy to teach GCSE and A-Level Physics and Mathematics.  I aim to concentrate on helping tutees develop a intuitive unde...”

MyTutor guarantee

You may also like...

Other A Level Physics questions

A particle is accelerated uniformly from rest, so that after 10 seconds it has achieved a speed of 15 m/s. Find its acceleration and the distance it has covered.

A car is moving along a straight horizontal road, with a constant acceleration. The car passes point A, with a speed of ums(-1). 10 seconds later, passes point B, with a speed of 45 ms(-1). The distance from A to B is 300m. Find u.

On a speed/time graph: a) how would a constant deceleration be illustrated? b) how would you use the graph to calculate total distance travelled?

How do I find the half-life of radioactive isotope?

View A Level Physics tutors

Cookies:

We use cookies to improve our service. By continuing to use this website, we'll assume that you're OK with this. Dismiss

mtw:mercury1:status:ok