A satellite is orbiting around the earth near its surface. If its kinetic energy is doubled, then
There is no atmosphere on the moon because
The maximum kinetic energy of aplanet moving around the sun is at a position
A man waves his arms while walking. This is to
A missile is launched with a velocity less than escape velocity. The sum of its kinetic and potential energies is
Which of the following graphs represents the motion of a planet moving about the sun ?
Due to rotation of the earth the acceleration due to gravity g is
The escape velocity from the earth’s surface is 11 km/s. The escape velocity from a planet having twice the radius and same mean density as that of earth is
Two point masses each equal to 1 kg attract one another with a force of 10–10 N. The distance between the two point masses is (G = 6.6 × 10–11 MKS units)
Solution
According to Newton’s Gravitation Law
\(F_{g}=\frac{GM_{1}M_{2}}{r^{2}}\) here Fg=10-10 Newton,
m1= m2= 1kg,
G = 6.6 × 10-11
So \(r^{2}=\frac{GM_{1}M_{2}}{F_{g}}=\frac{6.6\times 10^{-11}\times 1\times 1}{10^{-10}}=0.66\)
or r = 0.8125 metre = 81.25 cm≈80cm
There are two bodies of masses 103kg and 105 kg separated by a distance of 1 km. At what distance from the smaller body, the intensity of gravitational field will be zero
