Gravitation

Question 1

Gravitational Force

Answer 1

Gm1m2/r2

Question 2

Gravitational force is medium independent

Answer 2

As well as conservative

Question 3

True or false

Sphere can be considered a point mass

Answer 3

True. But rods cannot be considered so

Question 4

Gravitational net force can be calculated by
1}Simple addition
2}Vector addition

Answer 4

Vector addition

Question 5

for rods we need to use

Answer 5

Integration

Question 6

Acceleration due to gravity

Answer 6

GM/R2

Question 7

As we go above the surface it becomes

Answer 7

g upon square of 1 plus h by r

Question 8

As we go below the surface it becomes

Answer 8

g times 1 minus d by r

Question 9

Axial rotation affects in the pattern

Answer 9

g minus r(omega)^2cos sq phi

Question 10

at equator phi = 0

Answer 10

hence g= g minus r omega sq i.e. min

Question 11

at poles phi = 90

Answer 11

hence g= g i.e. max

Question 12

Gravitational field is defined as

Answer 12

the space around a mass or system in which any other test mass experiences a grav. force

Question 13

Gravitational field strength is defined as

Answer 13

Force experienced by a unit test mass placed at a point in a grav. field

Question 14

Field due to point mass

Answer 14

GM by r sq

Question 15

Field due to uniform solid sphere

At external

Answer 15

GM by r sq

Question 16

Field due to uniform solid sphere

At internal point

Answer 16

GM r by R cube

Question 17

Field due to uniform spherical shell

at external

Answer 17

GM by r sq

Question 18

Field due to uniform spherical shell

at internal

Answer 18

zero

Question 19

Field due to uniform circular ring at a point on its axis

Answer 19

GMr by (R sq + r sq )^(3/2)

Question 20

Gravitational Potential

Answer 20

Work done by gravitational force in moving a test mass from one point to another point.

Question 21

Potential due to point mass

Answer 21

minus GM by r

Question 22

Potential due to solid sphere uniform

At external

Answer 22

minus GM by r

Question 23

Potential due to solid sphere uniform

at surface

Answer 23

Minus GM by R

Question 24

Potential due to solid sphere uniform

at internal

Answer 24

minus GM by R cube into(1.5 R sq - 0.5 r sq)

Question 25

Potential due to uniform thin spherical shell

at external

Answer 25

minus GM by r

Question 26

Potential due to uniform thin spherical shell

at internal

Answer 26

minus GM by R

Question 27

potential due to uniform ring at some point on its axis

Answer 27

minus GM upon underroot of R sq + r sq

Question 28

potential can be added

Answer 28

Directly (Simple addition)

Question 29

Field strength can be added

Answer 29

BY vector addition

Question 30

V equals to

Answer 30

minus integration of Edx

Question 31

E equals to

Answer 31

minus dV by dR

Question 32

Gravitational potential energy

Answer 32

minus of work done by gravitational forces in bringing a body from infinity to present position.

Question 33

Formula for gravitational potential

Answer 33

minus of integration of F.dr {Limits: infinity to r}

Question 34

Gravitational potential energy of a two particle system

Answer 34

minus Gm1m2 by r

Question 35

For n particle system

Answer 35

Just add up all possible two member pairs

P.S. there will be { n into n-1 by 2 } no of pairs

Question 36

Gravitational potential energy of a particle on earth’s surface

Answer 36

minus of GMm by r

Question 37

Difference in potential energy

Answer 37

mgh by (1 plus h by R)

Question 38

Binding Energy

Answer 38

|Total energy|

Question 39

Escape velocity

Answer 39

underroot of (2gR)