phys ct

Question 1

systematic vs random errors

Answer 1

systematic: all readings being above or below the true readings by a fixed amount
random: readings being scattered about a mean value

Question 2

accuracy vs precision

Answer 2

accuracy: degree of closeness of mean value of measurements to true value
precision: degree of agreement between repeated measurements of the same quantity

Question 3

4 kinematics equations

Answer 3

v = u + at
s = 1/2 (u+v)t
s = ut + 1/2at^2
v^2 = u^2 + 2as

Question 4

newtons 1st law of motion

Answer 4

a body a rest will remain at rest or in uniform motion continues in its state in a straight line unless a resultant external force acts on it (inertia)

Question 5

newtons 2nd law of motion

Answer 5

the rate of change of momentum of a body is proportional to the resultant force acting on it and occurs in the direction of the force

Question 6

newtons 3rd law of motion

Answer 6

if body a exerts a force on body b, body b exerts an equal and opposite force on body a

Question 7

mass vs weight

Answer 7

mass: property which results in a change in motion
weight: force experienced by a mass in a gravitational field

Question 8

action reaction

Answer 8

forces equal in magnitude opposite in direction, same type of forces on 2 diff bodies acting at the same time

Question 9

impulse

Answer 9

product of force acting on object and time (delta T) for which force acts

Question 10

principle of conservation of momentum

Answer 10

when bodies in a system interact, total momentum of the system remains constant

Question 11

impulse formula

Answer 11

delta p = f delta t

Question 12

elastic collision ke conserved formula

Answer 12

u1-u2 = v2-v1

Question 13

momentum conserved formula

Answer 13

m1u1+m2u2=m1v1+m2v2

Question 14

force parallel to slope equation

Answer 14

mg sin theta/mg cos theta

Question 15

Hooke’s law

Answer 15

extension of body directly proportional to the applied load if limit of proportionality is not exceeded

Question 16

archimedes principle

Answer 16

upthrust on body in fluid equal to weight of fluid displaced by body

Question 17

principle of flotation

Answer 17

for object floating in equilibrium, upthrust equal in magnitude and opposite in direction of weight of object

Question 18

center of gravity

Answer 18

point at where weight of object appears to act

Question 19

conditions for equilibrium

Answer 19

no net force zero moments

Question 20

epe formula

Answer 20

1/2kx^2
1/2 fx

Question 21

pressure in fluid formula

Answer 21

hp(density)g

Question 22

upthrust formula

Answer 22

weight of fluid displaced = p(density)gv

Question 23

power formula

Answer 23

force x velocity
energy / time

Question 24

work done formula

Answer 24

f costheta x s

Question 25

work done by gas formula

Answer 25

p change in volume

Question 26

angular velocity

Answer 26

rate of change of angular displacement with respect to time

Question 27

period formula

Answer 27

time taken to make 1 complete revolution

Question 28

angular velocity formula

Answer 28

w=v/r w=2pi/T w=2pif

Question 29

centripetal acceleration formula

Answer 29

a=vw a=rw^2 a=v^2/r

Question 30

centripetal force formula

Answer 30

f=mvw f=mrw^2 f=mv^2/r

Question 31

tension (in circle) formula

Answer 31

t=mv^2/r

Question 32

formula: tension cos theta tension sin theta tan theta

Answer 32

tcostheta = mg tsintheta = mv^2/r tan theta = v^2/rg

Question 33

centripetal acceleration

Answer 33

acceleration towards center of circular motion

Question 34

velocity at top of circle formula

Answer 34

N + W = F N + mg = mv^2/r when N = 0, vmin=rootgr

Question 35

velocity at bottom of circle formula

Answer 35

1/2mvbot^2 = 1/2mvtop^2 + mg(2r) 1/2mvbot^2 = 1/2mgr+mg(2r) vbot=root5gr

Question 36

tension/normal force formula at top and at bottom

Answer 36

ttop/ntop + mg = mv^2/r stop/ntop = mv^2/r - mg tbot/nbot - mg = mv^2/r tbot/nbot = mv^2/r + mg

Question 37

tension of rod chasing formula

Answer 37

t+mgcos theta = mv^2/r t = mv^2/r -mg cos theta

Question 38

gravitational force formula

Answer 38

F = GMm/r^2

Question 39

newtons law of gravitation

Answer 39

2 point masses attract each other with a force that is directly proportional to the product of their masses and inversely proportionate to the square of distance between them

Question 40

gravitational field

Answer 40

region in which mass placed in that region experiences a gravitational force

Question 41

gravitational field strength

Answer 41

gravitational force experienced per unit mass at that point

Question 42

gravitational potential energy

Answer 42

mass at a point in gravitational field, WD by external force in bringing mass from infinity to that point

Question 43

gravitational field formula

Answer 43

g=F/m g=GM/r^2

Question 44

gravitational potential energy formula

Answer 44

U=-GMm/r -ve !!

Question 45

gravitational potential

Answer 45

WD per unit mass by external force in bringing small mass from infinity to the point

Question 46

gravitational potential formula

Answer 46

theta w line = -GM/r = U/m -ve as Gf is attractive in nature, bring mass from infinity to a point on field, force opposite in direction of displacement

Question 47

escape velocity

Answer 47

minimum speed to escape from gravitational influence

Question 48

escape velocity formula

Answer 48

GMm/Rearth + 1/2 mv^2 >/= o v = root (2GM/Rearth) v = root (2 g rearth)

Question 49

kinetic energy (gravitational field)

Answer 49

1/2 GMm/r

Question 50

potential energy (gravitational field)

Answer 50

-GMm/r

Question 51

total energy (gravitational field)

Answer 51

-1/2 GMm/r

Question 52

for body to orbit around earth formula

Answer 52

GMm/r^2 = mv^2/r v orbital = root GM/r GMm/r^2 = mrw^2 = mr(2pi/T)^2 T^2 = 4pi^2/GM r^3

Question 53

force at equator and polar region

Answer 53

equator: mg = mg-ma g=g-a (a-centripetal acceleration) polar region: mg=mg g=g

Question 54

Kepler's third law

Answer 54

gf provides centripetal force necessary for circular motion of plant around sun square of period of revolution of planets directly proportional to cubes of mean distances from the sun