PHYSICS

Question 1

what does this mean: element undergoes B decay a nuclear neutron is converted to nuclear proton as the nucleus EMITS AN E

Answer 1

emitting an electron - -1e

Question 2

N/m2 is equal to

Answer 2

kg/m x s2

Question 3

where does sound travel most rapidly

Answer 3

greatest is solid bc of strong bonds and close proximity - then water then gas

Question 4

a nearsighted person can only focus on ____ and far ones are

Answer 4

nearby obj, far ones are blurry

Question 5

with myopia is the focal length shorter or not than it should be

Answer 5

yes, shorter, so rays from distant obj form a sharp img IN FRONT OF RETINA

Question 6

____occurs when your eyeball is shorter than normal or your cornea is curved too little.

Answer 6

Farsightedness - the focal length is longer than it should be, visual image being focused behind the retina rather than directly on it, could be bc eyeball is too small

Question 7

the terminal voltage is the ____

Answer 7

is the voltage provided to the external components of the circuit - V= electromotive force minus ir (current times resistance)

Question 8

when going from n=2, to n=3 what is req

Answer 8

energy is required and atoms GAINS ENERGY

Question 9

when a light wave pass from air to glass, what changes in speeds

Answer 9

light slow down, and speed will speed up - light slows bc the index of refraction in the glass is greater than air,

Question 10

light can be carried along a distance within a transparent material by means of total internal reflection because of

Answer 10

reflection - optical property

Question 11

kinematic equation to find distance

Answer 11

vit + 1/2 a t2, = d + vt

Question 12

formula for vf

Answer 12

vf2 = vi2 + 2ad & vi + at

Question 13

when ask for ratio height of image to the height of the object is what

Answer 13

4/3 : 4 - 1/3

Question 14

power is defined as the rate of doing

Answer 14

work/ t

Question 15

a 15 ev photon collides with and ionizes a H atom, if atom was originally in the ground state (ionization potential = 13.6) what is KE of ejected electron

Answer 15

15 - 13.6 = 1.4

Question 16

an obj with 15 g initally is immersed in benzene and suffers an loss of 5 g (placed in wate/fluid), what is specfic gravity of obj, if the specific gravity of benzene is 0/7

Answer 16

first buoyant force is equal to weight of fluid displaced by obj so it would be the 5 g that was diplaced - no ratio of obj mass to fluid mass is 15:5 = 3 now times this by specifc gravity of benzene which was 0/7 - 2.1

Question 17

pipe open at both ends what would be formula for wavelength

Answer 17

2L - length

Question 18

if pipe is closed then what is the formula for wavelength

Answer 18

4L

Question 19

in series explain V, I, R

Answer 19

V is added up, I is same, R is added up

Question 20

with parallel explain V,I,R

Answer 20

V is same, I is added, R is added inverse

Question 21

when we neglect viscoity where will stream have the highest pressure

Answer 21

point of max diameter =

Question 22

person is far sight and they clearly see no closer than 300 cm what does this mean

Answer 22

300 cm is the total from bw the obj and the image distances must be at least 300 cm so then the mirror must be half this distance which is 150 cm - plane mirror

Question 23

sounds cannot propgrate throught this medium

Answer 23

vacuum

Question 24

person standing comparing the arterial bp measured in arm compared to leg, the leg woule

Answer 24

be greater because the column of blood bw the arm and the leg has a hydrostatic pressure – independant of blood flow or viscosity

Question 25

hydrostatic presure formula

Answer 25

rgh - r is desnity - pressure at bottom of tube

Question 26

electric power for transmission over long distances is stepped up to a very high voltage in order to

Answer 26

cut down the heat loss in transmission wires

Question 27

if it says adj length bw crest and trought that is only equal

Answer 27

to half wavelenth - have to times it by 2

Question 28

formual for work with m and h

Answer 28

mgh