Thermal physics

Question 1

How do you calculate the work done by a gas when its volume decreases, while its pressure stays constant.

Answer 1

/\W=p/\v

W=pv

Question 2

Kinetic Theory assumptions:

Answer 2

• There are many molecules in the gas, so that average figures are
representative of the whole.
• The molecules are moving rapidly and randomly.
• The behaviour of the molecules can be described by Newtonian
mechanics.
• The molecules are far apart(compared until their diameters)and have
no pull on each other.
• Any forces acting, do so only during collisions and then only for a
very short time compared with the time between collisions.
• The collisions are elastic (kinetic energy is conserved).
• The total volume of the molecules is small compared to the volume
of the gas as a whole.

Question 3

Adiabatic:

Answer 3

No energy is gained or lost to the surroundings (closed system)

Question 4

Boyle’s Law

Answer 4

P ~ 1/v Curve moves away from origin at increase temp

Question 5

Charles Law

Answer 5

V ~ T

Question 6

Pressure Law

Answer 6

P ~ T

Question 7

Isothermic

Answer 7

Constant temperature

Question 8

Isobaric

Answer 8

Constant pressure

Question 9

Define the tesla.

Answer 9

The tesla is the (strength) of the magnetic field/flux density that
produces a force of 1 newton in a wire of length 1m with 1 ampere

Question 10

In a cyclotron:
Explain why it is not possible for the magnetic field to alter the speed of a proton
while it is in one of the D-shaped regions

Answer 10

-It is not possible as the force (due to the magnetic field) is
perpendicular to the motion/direction of travel/velocity (it can only change the particles direction)