Gravitation

The value of Universal Gravitational constant is

• 6.673X10^-11 Nm^-2kg²

• 6.673X10^-11 Nm²kg²

• 6.673X10^-11 Nm² kg^-2

• 6.673 x10^-11 N m^-2 kg^-2

which are the following is Newton’s Law of gravitation ?

• $W=\frac{GMm}{r}$

• $F\ =\frac{GMm}{r^2}$

• $V\ =\sqrt{\frac{GM}{r}}$

• $g=-\ \frac{GM}{r}$

State the definition of Gravitational field strength

• Gravitational force per unit time acting on a body at a point in a gravitational field

• The force between two bodies of mass M and m is directly proportional to the product of their masses

• Gravitational force per unit mass acting on a body at a point in a gravitational field

the gravitation force of a particle X of mass  $m_1$  on another particle Y mass  $m_2$ is  $F_1$  . the gravitational force of Y on X is $F_2$  . if  $m_1>m_2$  , which of the following statements about the gravitational force  $F_1$  and  $F_2$  is correct ?

• magnitude of $F_1$  is greater than the magnitude of  $F_2$  

•  $F_{1\ }$  and  $F_2$  in same directions

•  $F_{1\ }$  and  $F_2$  act along the line joining  $m_1$  and  $m_2$  

•  $F_1$  and  $F_2$  form an potential energy pair

A satelite is at a distance,  $r$  from the centre of Earth. by using Newton's Second Law of Gravitation, determine the speed,  $v$  of the satelite motion

•  $v\ =\frac{GMf}{m}$  

•  $v\ =\ \frac{GMm}{r}$  

•  $v=2\pi\ \sqrt{\frac{r^3}{GM}}$  

•  $v\ =\ \sqrt{\frac{GM}{r}}$