Question

Use the universal law of gravitation to solve the following problemsTwo cars of mass 3000kg are 2m apart. What is the force between them?The force of gravity between a planet and its moon is 371N. If the planet has a mass of 4*10^22kg and the moon has a mass of 5*10^5kg, what is the distance between their centers?The force of gravity between Tim and John is 1.85*10^-9N. If they are 18m apart and Tim has a mass of 120kg. What is johns mass?

Answer 1

Given,

Mass of the cars, m₁=m₂=3000 kg

The distance between the cars, r=2m

From the universal law of gravitation,

`F=(Gm_1m_2)/(r^2)`

Where G is the gravitational constant. The value of G is 6.67×10⁻¹¹ N·m²/kg²

On substituting the known values in the above equation,

`F=(6.67*10^(-11)*3000*3000)/(2^2)=1.05*10^(-4)\text{ N}`

Therefore the force between the cars is 1.05×10⁻⁴ N