The correct answers are: Options 2,4 and, 5
2)He solved Ptolemy’s model by proving elliptical orbits.
4)He determined that planets move faster when closer to the Sun.
5)He discovered laws of planetary motion.
Answer: 50.7 J
Explanation:
Given
mass of lion is 
The initial speed of the lion is 
increased speed of lion is 
Initially, its kinetic energy is 
Final kinetic energy 
work did by lion after speed up is 
![\Rightarrow W=\dfrac{1}{2}\times 2.6[8^2-5^2]\\\\\Rightarrow W=1.3\times [39]=50.7\ J](https://tex.z-dn.net/?f=%5CRightarrow%20W%3D%5Cdfrac%7B1%7D%7B2%7D%5Ctimes%202.6%5B8%5E2-5%5E2%5D%5C%5C%5C%5C%5CRightarrow%20W%3D1.3%5Ctimes%20%5B39%5D%3D50.7%5C%20J)
There are two equal forces of gravity between the Earth and the Moon.
One force pulls the Moon toward the Earth.
The other force pulls the Earth toward the Moon.
If only this gravity suddenly switched off, then the moon would
continue to orbit the Sun, very much as it does now.
If ALL gravity suddenly switched off, then . . .
-- the Moon would stop orbiting the Earth and would sail away, in
a straight line and at the speed it had when gravity disappeared;
-- the Earth would stop orbiting the Sun and would sail away, in
a straight line and at the speed it had when gravity disappeared;
-- all the gases surrounding the Earth ... which we call "air" ... would
start drifting away, and expanding into a giant cloud of gas, and stop
being an atmosphere;
-- the Sun would completely fall apart, expand into a giant cloud of gas,
and stop being a star.
