Physics
Mechanics
Easy

Question

A point mass is orbiting a significant mass M lying at the focus of the elliptical orbit having major          and minor axes given by 2a and 2b respectively. Let r be the distance between the mass M and the   end point  of major axis. Velocity of the particle can be given as

  1. fraction numerator a b over denominator r end fraction square root of fraction numerator G M over denominator a cubed end fraction end root
  2. fraction numerator a b over denominator r end fraction square root of fraction numerator G M over denominator b cubed end fraction end root
  3. fraction numerator a b over denominator 2 r end fraction square root of G over r end root
  4. fraction numerator 2 a b over denominator r end fraction square root of open parentheses fraction numerator a plus b over denominator 2 end fraction close parentheses cubed end root

The correct answer is: fraction numerator a b over denominator r end fraction square root of fraction numerator G M over denominator a cubed end fraction end root


    text  Gravitational force  end text equals text  Centripetal force  end text not stretchy rightwards double arrow fraction numerator G M m over denominator r squared end fraction equals fraction numerator m v squared over denominator r end fraction
    not stretchy rightwards double arrow fraction numerator G M over denominator r squared end fraction equals v squared over r not stretchy rightwards double arrow fraction numerator G M over denominator a squared end fraction equals fraction numerator left parenthesis a omega right parenthesis squared over denominator a end fraction not stretchy rightwards double arrow omega squared equals fraction numerator G M over denominator a cubed end fraction
    Here r is the radius of curvature .From Kepler's law, time period is given by.
    T equals 2 pi square root of fraction numerator a cubed over denominator G M end fraction end root equals fraction numerator 2 pi a b over denominator r v end fraction open parentheses fraction numerator d A over denominator d t end fraction equals fraction numerator v r over denominator 2 end fraction not stretchy rightwards double arrow d t equals T equals fraction numerator 2 d A over denominator 1 straight percent sign end fraction equals fraction numerator 2 over denominator r v end fraction pi a b close parentheses
    v equals fraction numerator a b over denominator r end fraction square root of fraction numerator G M over denominator a cubed end fraction end root

    Related Questions to study

    Mechanics
    Physics

    text  The gravitational field in a region is  end text 10 straight N divided by kg left parenthesis straight i with not stretchy hat on top minus straight j with not stretchy hat on top right parenthesis. text  Then the work done by  end text
g r a v i t a t i o n a l space f o r c e space t o space s h i f t space s l o w l y space a space p a r t i c l e space o f space m a s s space 1 k g space f r o m space p o i n t space left parenthesis 1 m comma space 1 m right parenthesis space t o space a space
p o i n t space left parenthesis 2 m comma space – 2 m right parenthesis space i s space minus space space

    text  The gravitational field in a region is  end text 10 straight N divided by kg left parenthesis straight i with not stretchy hat on top minus straight j with not stretchy hat on top right parenthesis. text  Then the work done by  end text
g r a v i t a t i o n a l space f o r c e space t o space s h i f t space s l o w l y space a space p a r t i c l e space o f space m a s s space 1 k g space f r o m space p o i n t space left parenthesis 1 m comma space 1 m right parenthesis space t o space a space
p o i n t space left parenthesis 2 m comma space – 2 m right parenthesis space i s space minus space space

    PhysicsMechanics
    Mechanics
    Physics

    Two spheres of masses m and M are situated in air and the gravitational force between them is F. The space around the masses is now filled with a liquid of specific gravity 3. The gravitational force will now be –

    Two spheres of masses m and M are situated in air and the gravitational force between them is F. The space around the masses is now filled with a liquid of specific gravity 3. The gravitational force will now be –

    PhysicsMechanics
    Mechanics
    Physics

    A point mass m0 is placed at distance R/3 from the centre of a spherical shell of mass m and radius R. The gravitational force on the point mass m0 is -

    A point mass m0 is placed at distance R/3 from the centre of a spherical shell of mass m and radius R. The gravitational force on the point mass m0 is -

    PhysicsMechanics
    parallel
    Mechanics
    Physics

    Two particles each of mass m are placed at A and C as such AB = BC = L. The gravitational force on the third particle placed at D at a distance L metre on the perpendicular bisector of the line AC, is –

    Two particles each of mass m are placed at A and C as such AB = BC = L. The gravitational force on the third particle placed at D at a distance L metre on the perpendicular bisector of the line AC, is –

    PhysicsMechanics
    Mechanics
    Physics

    The magnitude of the gravitational field at distances r1 & r2 from the centre of a uniform sphere of radius R & mass M are F1 & F2 respectively then

    The magnitude of the gravitational field at distances r1 & r2 from the centre of a uniform sphere of radius R & mass M are F1 & F2 respectively then

    PhysicsMechanics
    Mechanics
    Physics

    A spherical hole is made in a solid sphere of radius R. The mass of the sphere before hollowing was M. The gravitational field at the centre of the hole due to the remaining mass is

    A spherical hole is made in a solid sphere of radius R. The mass of the sphere before hollowing was M. The gravitational field at the centre of the hole due to the remaining mass is

    PhysicsMechanics
    parallel
    Mechanics
    Physics

    text  The gravitational field in a region is  end text 10 straight N divided by kg left parenthesis i with not stretchy hat on top minus j with not stretchy hat on top right parenthesis. text  The work done by  end text
g r a v i t a t i o n a l space f o r c e space t o space s h i f t space s l o w l y space a space p a r t i c l e space o f space m a s s space 1 space k g space f r o m space p o i n t space left parenthesis 1 m comma space 1 m right parenthesis space t o space a space
p o i n t space left parenthesis 2 m comma space minus 2 m right parenthesis space i s space space space space space

    text  The gravitational field in a region is  end text 10 straight N divided by kg left parenthesis i with not stretchy hat on top minus j with not stretchy hat on top right parenthesis. text  The work done by  end text
g r a v i t a t i o n a l space f o r c e space t o space s h i f t space s l o w l y space a space p a r t i c l e space o f space m a s s space 1 space k g space f r o m space p o i n t space left parenthesis 1 m comma space 1 m right parenthesis space t o space a space
p o i n t space left parenthesis 2 m comma space minus 2 m right parenthesis space i s space space space space space

    PhysicsMechanics
    Mechanics
    Physics

    There are two bodies of masses 100 kg and 10000 kg separated by a distance 1 m. At what distance from the smaller body, the intensity of gravitational field will be zero?

    There are two bodies of masses 100 kg and 10000 kg separated by a distance 1 m. At what distance from the smaller body, the intensity of gravitational field will be zero?

    PhysicsMechanics
    Mechanics
    Physics

    A spherical hole is made in a solid sphere of radius R. The mass of the sphere before hollowing was M. The gravitational field at the centre of the hole due to the remaining mass is –

    A spherical hole is made in a solid sphere of radius R. The mass of the sphere before hollowing was M. The gravitational field at the centre of the hole due to the remaining mass is –

    PhysicsMechanics
    parallel
    Mechanics
    Physics

    A mass m is placed in the cavity inside a uniform hollow sphere of mass M as shown in the figure. What is the gravitational force on the mass m?

    A mass m is placed in the cavity inside a uniform hollow sphere of mass M as shown in the figure. What is the gravitational force on the mass m?

    PhysicsMechanics
    Mechanics
    Physics

    T w o space l e a d space s p h e r e s space o f space s a m e space r a d i u s space a r e space i n space c o n t a c t space w i t h space e a c h space o t h e r. space T h e space
g r a v i t a t i o n a l space f o r c e space o f space a t t r a c t i o n space b e t w e e n space t h e m space i s space F. space I f space t w o space l e a d space s p h e r e s space
o f space d o u b l e space t h e space p r e v i o u s space r a d i u s space a r e space i n space c o n t a c t space w i t h space e a c h space o t h e r comma space t h e space
g r a v i t a t i o n a l space f o r c e space o f space a t t r a c t i o n space b e t w e e n space t h e m space w i l l space b e

    T w o space l e a d space s p h e r e s space o f space s a m e space r a d i u s space a r e space i n space c o n t a c t space w i t h space e a c h space o t h e r. space T h e space
g r a v i t a t i o n a l space f o r c e space o f space a t t r a c t i o n space b e t w e e n space t h e m space i s space F. space I f space t w o space l e a d space s p h e r e s space
o f space d o u b l e space t h e space p r e v i o u s space r a d i u s space a r e space i n space c o n t a c t space w i t h space e a c h space o t h e r comma space t h e space
g r a v i t a t i o n a l space f o r c e space o f space a t t r a c t i o n space b e t w e e n space t h e m space w i l l space b e

    PhysicsMechanics
    Mechanics
    Physics

    T w o space m e t a l space s p h e r e s space e a c h space o f space r a d i u s space ‘ r ’ space a r e space k e p t space i n space c o n t a c t space w i t h space e a c h space o t h e r. space I f space
d space i s space t h e space d e n s i t y space o f space t h e space m a t e r i a l space o f space t h e space s p h e r e comma space t h e n space t h e space g r a v i t a t i o n a l space f o r c e space
b e t w e e n space t h o s e space s p h e r e s space i s space p r o p o r t i o n a l space t o

    T w o space m e t a l space s p h e r e s space e a c h space o f space r a d i u s space ‘ r ’ space a r e space k e p t space i n space c o n t a c t space w i t h space e a c h space o t h e r. space I f space
d space i s space t h e space d e n s i t y space o f space t h e space m a t e r i a l space o f space t h e space s p h e r e comma space t h e n space t h e space g r a v i t a t i o n a l space f o r c e space
b e t w e e n space t h o s e space s p h e r e s space i s space p r o p o r t i o n a l space t o

    PhysicsMechanics
    parallel
    Mechanics
    Physics

    T w o space p a r t i c l e s space e a c h space o f space m a s s space ‘ m ’ space a r e space p l a c e d space a t space A space a n d space C space a r e space s u c h space A B equals B C equals L. space
T h e space g r a v i t a t i o n a l space f o r c e space o n space t h e space t h i r d space p a r t i c l e space p l a c e d space a t space D space a t space a space d i s tan c e space L space o n space t h e space
p e r p e n d i c u l a r space b i s e c t o r space o f space t h e space l i n e space A C space i s

    T w o space p a r t i c l e s space e a c h space o f space m a s s space ‘ m ’ space a r e space p l a c e d space a t space A space a n d space C space a r e space s u c h space A B equals B C equals L. space
T h e space g r a v i t a t i o n a l space f o r c e space o n space t h e space t h i r d space p a r t i c l e space p l a c e d space a t space D space a t space a space d i s tan c e space L space o n space t h e space
p e r p e n d i c u l a r space b i s e c t o r space o f space t h e space l i n e space A C space i s

    PhysicsMechanics
    Mechanics
    Physics

    T h r e e space i d e n t i c a l space p a r t i c l e s space e a c h space o f space m a s s space “ m ” space a r e space a r r a n g e d space a t space t h e space c o r n e r s space o f space a n space
e q u i l a t e r a l space t r i a n g l e space o f space s i d e space “ L ”. space I f space t h e y space a r e space t o space b e space i n space e q u i l i b r i u m comma space t h e space s p e e d space w i t h space
w h i c h space t h e y space m u s t space r e v o l v e space u n d e r space t h e space i n f l u e n c e space o f space o n e space a n o t h e r ’ s space g r a v i t y space i n space a space
c i r c u l a r space o r b i t space c i r c u m s c r i b i n g space t h e space t r i a n g l e space i s

    T h r e e space i d e n t i c a l space p a r t i c l e s space e a c h space o f space m a s s space “ m ” space a r e space a r r a n g e d space a t space t h e space c o r n e r s space o f space a n space
e q u i l a t e r a l space t r i a n g l e space o f space s i d e space “ L ”. space I f space t h e y space a r e space t o space b e space i n space e q u i l i b r i u m comma space t h e space s p e e d space w i t h space
w h i c h space t h e y space m u s t space r e v o l v e space u n d e r space t h e space i n f l u e n c e space o f space o n e space a n o t h e r ’ s space g r a v i t y space i n space a space
c i r c u l a r space o r b i t space c i r c u m s c r i b i n g space t h e space t r i a n g l e space i s

    PhysicsMechanics
    Mechanics
    Physics

    T w o space l e a d space b a l l s space o f space m a s s e s space m space a n d space 5 m space h a v i n g space r a d i i space R space a n d space 2 R space a r e space s e p a r a t e d space b y space
12 R. space I f space t h e y space a t t r a c t space e a c h space o t h e r space b y space g r a v i t a t i o n a l space f o r c e comma space t h e space d i s tan c e space c o v e r e d space b y space
s m a l l space s p h e r e space b e f o r e space t h e y space t o u c h space e a c h space

    T w o space l e a d space b a l l s space o f space m a s s e s space m space a n d space 5 m space h a v i n g space r a d i i space R space a n d space 2 R space a r e space s e p a r a t e d space b y space
12 R. space I f space t h e y space a t t r a c t space e a c h space o t h e r space b y space g r a v i t a t i o n a l space f o r c e comma space t h e space d i s tan c e space c o v e r e d space b y space
s m a l l space s p h e r e space b e f o r e space t h e y space t o u c h space e a c h space

    PhysicsMechanics
    parallel

    card img

    With Turito Academy.

    card img

    With Turito Foundation.

    card img

    Get an Expert Advice From Turito.

    Turito Academy

    card img

    With Turito Academy.

    Test Prep

    card img

    With Turito Foundation.