1st Monthly Challenge - Physics (17th July 2021, Saturday)

What did Copernicus, Brahe, Galileo and Johannes Keppler had in common?

• They discovered gravity.

• They discovered new planets.

• They discovered that planets orbit around the Sun.

• They are all scientists from the same country.

Which of the following theories were not developed by Newton?

• Calculus

• Laws of Motion

• Universal Law of Gravitation

• General Relativity

Choose the CORRECT statement.

• Johannes Kepler discovered that planets move around the Sun in circular orbits.

• Galileo got into trouble with the government of his time because he believed that the moon revolved around the Earth.

• Newton got into a bitter rivalry with Leibniz over his law of gravity.

• Tycho Brahe was a Danish astronomer who discovered that planets revolved around the Sun.

Two objects with masses $m_1$  and  $m_2$  separated by distance  $r$  exert a gravitational force of magnitude $F$ on each other. A third object with mass  $m_3$  is three times of  $m_2$ and is separated from  $m_1$  by twice the distance  $r$  . What is the magnitude of gravitational force between  $m_1$  and  $m_3$  ?

• 0.75 $F$  

• 1.33 $F$  

• 3 $F$  

• 0.25 $F$  

Choose the WRONG statement.

• Newton's law of gravity helped to discover the planet Neptune.

• Newton came up with three laws of motion.

• Newton's law of gravity helped sending human to the moon.

• Newton's gravity could explain the orbit of planet Mercury around the Sun.

What exactly did Einstein discover which would later prove Newton's law of gravity to be inaccurate?

• Gravity makes time runs faster.

• Gravity is a force not included in the Standard Model.

• Nothing in the universe can travel faster than light.

• The gravitational acceleration on Earth is 9.80 m/s^2.

Which of the following DOES NOT describe the failure of Newton's Law of Gravity.

• Newton did not relate gravity with acceleration.

• Newton's formula was unable to predict the orbit of planet Mercury.

• Newton's gravity acts instantaneously.

• Newton's gravity is a force that acts mysteriously at a distance without any contact between two objects.

"Light always takes the shortest path." This statement refers to

• Kepler's Third Law

• Einstein's Theory of Special Relativity.

• Newton's Law of Motion

• Fermat's Principle

"Space-time tells matter how to __________. Matter tells space-time how to __________." --- By ____________.

• move; curve; Steven Weinberg

• curve; move; Marcel Grossman

• move; curve; John Wheeler

• curve; move; Albert Einstein

To Einstein, gravity is

• A force that causes spacetime to curve.

• Curvature of spacetime itself.

• Caused by Graviton.

• A fundamental force of nature.