Question

What is the force of gravity experienced by an object of mass 2 kg placed on the surface of the earth? Given that mass of the earth = 6 x 10²⁴ kg; the radius of the earth = 6.4 x 10⁶ m and G = 6.7 x 10^-11 Nm² kg^-2.

Answer 1

Given:

The mass of an object (m) = 2 kg.

The mass of the earth (M) = 6 x 10²⁴ kg.

The radius of the earth (R) = 6.4 x 10⁶ m.

Universal gravitational constant (G) = 6.7 x 10^-11 Nm² kg^-2.

Required to find:

The magnitude of the force of gravity experienced by the object (F).

Solution:

We know that the magnitude of the force of gravity (F) is given by $F=\frac{GMm}{R^2}$.

By substituting the given values in the above equation, $$\begin{gathered} F=\frac{(6.7x{10}^{-11})x(6x{10}^{24})x\left(2\right)}{{(6.4x{10}^6)}^2}=\frac{80.4x{10}^{13}}{40.96x{10}^{12}} \\ =1.96x10=19.6N \end{gathered}$$

Hence, the magnitude of the force of gravity experienced by the object is 19.6 N.