Question

Pedro está realizando sus tareas de Física. Durante un descanso observa la goma de borrar y el lápiz sobre la mesa, y se pregunta por qué no se mueven el uno hacia el otro, si entre estos objetos existe atracción gravitatoria, como le han explicado en clase. a) ¿Realmente existe una fuerza de atracción gravitatoria entre el lápiz y la goma?

Answer 1

Answer:

The gravitational force between these two objects is around $F_{g}=6.674*10^{-11} N$

Explanation:

The gravitational force can be written as:

$F_{g}=G\frac{m_{1}m_{2}}{r^{2}}$

Here:

• G is the gravitational constant $G = 6.674*10^{-11} m^{3}kg^{-1}s^{-2}$
• m(1) is the first mass
• m(2) is the second mass
• r is the distance between two bodies.

If we see, the gravitational constant is a very small number, therefore the gravitational force is representative just when we have to massive bodies. Let's suppose that the mass of the pencil is 0.1 kg and the eraser is 0.1 kg too, the distance between them would be around 10 cm or 0.1 m, for instance.

Now let's calculate the gravitational force of these two bodies.

$F_{g}=G\frac{0.01*0.01}{0.1^{2}}$          

$F_{g}=6.674*10^{-11} N$

As we see it is very small force, so it is negligible relation to the earth gravitational force. That is why these two objects do not move towards each other.

I hope it helps you!