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
Verified Correct Answer: C.
Physical Principles & Numerical Solution
\(F= \frac{Gm_{1}m_{2}}{r^{2}}\)
\(m_{1} = 100kg\)
\(m_{2} = 20kg; r =1.2m\)
\(G= 6.67\times 10^{-11}\)
\(F = \frac{6.67\times 10^{-11}\times 100\times 20}{(1.2)^{2}} = 9.26\times 10^{-8}\)
Gravitational force is always attractive. Therefore, the net force acting on object Q will pull it directly towards the larger mass, P.
Source: Myschool Past Questions Archive (Record #49788)