Gravitation

Question 1

state Newton’s law of gravitation?

Answer 1

every body in the universe attracts every other body with force directly proportional to the product of their masses and inversely proportional to the square of the distance between their centres.

Question 2

what is G?

Answer 2

universal gravitational constant
its value =6.673 × 10-11 Nm2 kg-2

Question 3

G is _______________ proportional m1 m1

Answer 3

directly

Question 4

G is _____________ proportional to d2

Answer 4

indirectly

Question 5

What is the difference between the gravitational force and the force of gravity?

Answer 5

Gravitational force acts between any two objects possessing mass.
Force of Gravity is a natural property of the earth due to which it attracts all objects near to it.

Question 6

what is F according to Newton’s law of gravitation?

Answer 6

F= G m1 m1/ d2

gravitational force of attraction

Question 7

mass of earth?

Answer 7

6×10^24 kg

Question 8

how do we find mass of the earth?

Answer 8

page 110

Question 9

formula for mass of the earth?

Answer 9

mE= gr2/G

g= gravitational accelerarion
r= distance or radius of the earth
G= gravitational constant

Question 10

what is gravitational field strength?

Answer 10

the gravitational force per unit mass.

how much gravitational force a body 1kg experiances.

Question 11

what is gravitational field?

Answer 11

a region in space around a massive object where other objects with mass experience a force of attraction due to gravity.

Question 12

g=
what is the value of g at the surface of earth?

g = gravitational field strength

Answer 12

F/m
10N/kg

Question 13

what is the radius of earth?

Answer 13

6.4x10^6 m

this is in meters in kilometers it would be 6,371 km

Question 14

the weight of an object on the earth is the result of __________________.

Answer 14

gravitational force of attraction b/w the Earth and the object.

Question 15

to find the mass of a planet what do we need to know?

Answer 15

gravitational acceleration
radius

same for star

Question 16

why acceleration due to gravity is same as gravitational field strength?

Answer 16

Newton’s 2nd law of motion
a=F/m
g= F/m

a is force per unit mass.(how much force causes acceleration.)
g is gravitational force per unit mass experiances.

Question 17

gravitational force =?

Answer 17

weight

Question 18

can there be different value for gravitational acceleraration?

Answer 18

yes
At the poles, you’re closer to the center of the Earth, so the gravitational force is a bit stronger.
At the equator, you’re farther away from the center because of the bulge, so the gravitational force is slightly weaker.
FMIGTN

less radius = more force

Question 19

does g depend on upons mass of the body?

g= gravitational acceleration

Answer 19

g=G Me/re2

in this equation g does not depend upon mass of the body

Question 20

what does gravitational acceleration depend upon?

Answer 20

radius of the earth
mass of the earth
g= G Me/re2

Question 21

what is the formula for acceleration due to gravity at a height h?

Answer 21

gh= G Me/(R+h)^2

Question 22

does gravitational acceleration decrease with increasing altitude?

Answer 22

No, g decreases but not with altitude.
gravitational force between two objects is inversely proportional to the square of the distance between them. As you move farther away from the Earth’s center, the distance between you and the center of the Earth increases, leading to a decrease in gravitational force and, consequently, a decrease in gravitational acceleration.

Question 23

what is a satellite?

Answer 23

naturally occruing or man-made object that orbits another object larger than itself by force of gravity.

Question 24

what is orbital velocity?

Answer 24

in circular orbit, a satellite has a constant tangential speed called orbital velocity.

Question 25

why the speed of a satellite should be kept constant and at stable speed?

Answer 25

high speed= move in elliptical orbit or escape. low speed = fall back to Earth

Question 26

formula for orbital velocity? ## Footnote derive it?

Answer 26

v=√Gme/re + h

Question 27

orbital speed doesn't depend upon ___________.

Answer 27

mass of satellite

Question 28

altitude of geostationary orbit?

Answer 28

35,700 km

Question 29

when finding orbital speed, the radius which is ____________should have matching units in m.

Answer 29

sum of Earth’s radius and height of satellite | always remember that!

Question 30

why Earth doesn't move towards the object becuase of its gravitational force?

Answer 30

the vast difference in mass b/w the Earth and typical objects. object's mass is minuscule compared to the Earth's mass, so the acceleration of the Earth caused by its gravitational attraction is immeasurably small.

Question 31

difference b/w gravitational force and universal gravitational constant?

Answer 31

gravity is the force itself the universal gravitational constant is a numerical value that helps us calculate the strength of that force.

Question 32

Gravitational acceleration decreases when _________________.

Answer 32

you move farther away from the center of the Earth. | decreases with increase in altitude.

Question 33

why is a satellite put into a **circular orbit**?

Answer 33

becuase in a circular orbit, a satellite has a CONSTANT tangential speed. | which is called orbital velocity.

Question 34

how to put a satellite in an orbit?

Answer 34

1. move it to a high altitude. 2. accelerate it to a required constant tangential speed using rockets.

Question 35

prove that gravitational **acceleration** of heavy or light object is same?

Answer 35

g=GMe/Re2 ## Footnote this shows that g doesn't depend upon mass of the object but mass of the earth & distance b/w their centers.

Question 36

the change in the value of g is significant only ________________. | g= gravitational acceleration

Answer 36

at large distances.

Question 37

define gh?

Answer 37

value of acceleration due to gravity at a height 'h' from the surface of the Earth.

Question 38

what is the formula and value of the orbital velocity of a satellite revolving close to the Earth? | derive it.

Answer 38

v=√g R R+h= R gh= g | g= gravitational acceleration R= radius of Earth ## Footnote R>>h becuase the satellite is revoling close to the Earth that's why height is negligible value= 8km/s 29,000km/h

Question 39

while solving numerical questions what units should be changed?

Answer 39

km to m g to kg