Two objects P and Q of masses 100kg and 20kg respectively are 1.2m apart on a horizontal surface. Calculate the net gravitational force acting on Q. \([G= 6.67 \times 10^{-11} Nm^{2}kg^{-2}]\)
A. \(1.11\times 10^{-7} N\) towards P B. \(1.11\times 10^{-7} N\) towards Q C. \(9.26\times 10^{-8} N\) towards P D. \(9.26\times 10^{-8} N\) towards Q
Correct Answer: D
Explanation
\(F= \frac{Gm_{1}m_{2}}{r^{2}}\) \(m_{1} = 100kg\) \(m_{2} = 20kg; r =1.2m\) \(G= 6.67\times 10^{-11}\) \(F = \frac{6.67\times 10^{-11}\times 100\times 20}{(1.2)^{2}} = 9.26\times 10^{-8}\) The acceleration of each object is inversely proportional to the mass, the lighter object will move a bit faster, hence. the force will act in the direction of Q.
