Physics Test A

Question 1

What are the characteristics of ideal fluids

Answer 1

no viscosity, no turbulence and are incompressible.

Question 2

young modulus

Answer 2

pressure (stress)/ Length (strain)

Question 3

what happens to light when it passes from one medium to another?

Answer 3

its frequency remains the same and its wavelength changes.

Question 4

define current

Answer 4

current is the movement of a charge between two points with different electric potentials.

Question 5

eletron volt (eV)

Answer 5

represents the energy acquired by an electron accelerating through a potential difference of 1 volt.

Question 6

Instantaneous Velocity definition

Answer 6

slope of the graph of the objects position with respect to time at the particular time T.

Question 7

Newtons 1st law

Answer 7

An object at rest remains at rest unless acted on by a net force, an object in motion remains in motion with constant velocity unless acted on by a net force

Question 8

Newtons 2nd Law

Answer 8

a net force applied to a body of mass m will result in that body undergoing an acceleration the same direction as the net force. F=ma

Question 9

Newtons 3rd Law

Answer 9

If body A exerts a force F on body B, then B exerts a force -F back on A (equal in magnitude opposite in direction)

Question 10

Archimedes Principle

Answer 10

deals with law of buoyancy.

Question 11

Pascal’s principle

Answer 11

when pressure is applied to a fluid in a sealed container it is evenly distributed

Question 12

whats fission

Answer 12

process in which a nucleus splits into two or more nuclei each having a smaller mass number than the original.
The fission process is a means by which a least stable nuclei (less energy binding per nucleon) becomes more stable ( more energy binding per nucleon)

Question 13

what makes a more stable element?

Answer 13

The most stable element is also the element with the highest energy binding per nucleon.

Question 14

fussion

Answer 14

two or more nuclei fuse together to form a new nuclei, the mass number of the resulting nuclei is bigger than the two fused ones.

Question 15

How does a standing wave occur for a tube closed at one end and open at the other?

Answer 15

a standing wave results when the wavelength is such that the closed end is a node and the open end is an antinode.

Question 16

what does the condition of resonance depend on?

Answer 16

Depends on the length of the tube and the wavelength of the wave

Question 17

elastic collision

Answer 17

the kinetic energy of the system before the collision equals the kinetic energy after the collision.
For all types of collision momentum is conserved.

Question 18

what is dispersion

Answer 18

dispersion is the variation of wave-speed with frequency in a medium; the separation of visible light into its constituent colors as a result of this variation.

Question 19

what is diffraction

Answer 19

diffraction is the bending off waves as a result of passing through a slit; the bending of waves around an obstacle.

Question 20

what is reflection

Answer 20

reflection is the change in direction of a wave at the boundary of a medium when the wave remains in the medium.

Question 21

what is polarization

Answer 21

polarization is the processes whereby all the electric field vectors of light are made parallel.

Question 22

what is the idea of the photoelectric effect

Answer 22

the idea is that electrons will be ejected from a metallic surface when the light of sufficient frequency is shone on the surface. From planks equation (E=hf) , the frequency of the light determines the energy. The electrons on the surface require a small energy called the work function in order for it to be liberated from the surface. The frequency of the light must be large enough so that the lights energy is at least as the work function or no electron will be emitted.

Question 23

what is heat convection?

Answer 23

convection is the transfer of energy to a region by the movement of a mass of heated material, as in rising hot air.

Question 24

what is heat radiation?

Answer 24

the process of energy transfer via electromagnetic waves.