1.1. State the definition of escape velocity.

1.2. The equation to calculate the escape velocity from a planet is given below: 

      v = $\sqrt{\frac{2GM}{r}}$

Calculate the escape velocity at the surface of the Earth.

1.3. State the orbital period of the Earth around the Sun. 

1.4. When comparing the orbital period, T, and the orbital radius, r, of Earth and Mars around the Sun, Kepler’s third law can be written as: 

          $\frac{{({T}_{E})}^{2}}{{({r}_{E})}^{3}}=\frac{{({T}_{M})}^{2}}{{({r}_{m})}^{3}}$

Where ${T}_{E}$  and  ${T}_{M}$ are the orbital periods of Earth and Mars respectively and ${r}_{E}$ and ${r}_{M}$ are the orbital radii of Earth and Mars respectively.

Use the following data to calculate the orbital radius of Mars, ${r}_{M}$

Orbital radius of the Earth ${r}_{E}$= 15 × 10¹⁰ m

Period of orbit of Mars  ${T}_{M}$= 1.9 Earth years