Here is the formatted response for the last task:

Evaluate the expression:
[tex]\[
\begin{aligned}
g & = G \frac{M}{R^2} \\
& = \frac{6.7 \times 10^{-11} \, \text{Nm}^2 \text{kg}^{-2} \times 6 \times 10^{24} \, \text{kg}}{\left(6.4 \times 10^6 \, \text{m}\right)^2}
\end{aligned}
\][/tex]



Answer :

To calculate the acceleration due to gravity, [tex]\( g \)[/tex], on the surface of the Earth, we use the formula:

[tex]\[ g = G \frac{M}{R^2} \][/tex]

where:
- [tex]\( G \)[/tex] is the gravitational constant, [tex]\( 6.7 \times 10^{-11} \, \text{N m}^2 \text{kg}^{-2} \)[/tex],
- [tex]\( M \)[/tex] is the mass of the Earth, [tex]\( 6 \times 10^{24} \, \text{kg} \)[/tex],
- [tex]\( R \)[/tex] is the radius of the Earth, [tex]\( 6.4 \times 10^6 \, \text{m} \)[/tex].

The given formula can be broken down into several steps for clarity:

1. Calculate the square of the Earth's radius:

[tex]\[ R^2 = \left(6.4 \times 10^6 \, \text{m}\right)^2 \][/tex]

The calculation of [tex]\( R^2 \)[/tex] yields:

[tex]\[ R^2 = 6.4 \times 10^6 \times 6.4 \times 10^6 = 40.96 \times 10^{12} \, \text{m}^2 \][/tex]

2. Multiply the gravitational constant by the Earth's mass:

[tex]\[ G \times M = 6.7 \times 10^{-11} \, \text{N m}^2 \text{kg}^{-2} \times 6 \times 10^{24} \, \text{kg} \][/tex]

The calculation of [tex]\( G \times M \)[/tex] gives us:

[tex]\[ G \times M = 40.2 \times 10^{13} \, \text{N m}^2 \text{kg}^{-1} \][/tex]

3. Divide the result from step 2 by the result from step 1 to find [tex]\( g \)[/tex]:

[tex]\[ g = \frac{G \times M}{R^2} = \frac{40.2 \times 10^{13} \, \text{N m}^2 \text{kg}^{-1}}{40.96 \times 10^{12} \, \text{m}^2} \][/tex]

4. Simplify the division:

[tex]\[ g = \frac{40.2 \times 10^{13}}{40.96 \times 10^{12}} \, \text{N kg}^{-1} \text{m}^{-1} \][/tex]

5. Perform the division:

The value simplifies to approximately:

[tex]\[ g = 9.814 \, \text{m/s}^2 \][/tex]

So, the acceleration due to gravity [tex]\( g \)[/tex] on the surface of the Earth is approximately [tex]\( 9.814 \, \text{m/s}^2 \)[/tex].