Consider a distant planet having a radius of 3,000 kilometres and unknown mass. If an object is dropped from a height of 1,500 kilometres, what will be its velocity just before it hits the ground? (Assume the acceleration due to gravity on planet’s surface is 3 m/s².)
(A) 3,000 m/s
(B) 1,000 m/s
(C) 2,000 m/s
(D) Mass of the planet is required
The escape velocity from the Earth’s surface is v. The escape velocity from the surface of another planet having radius four times that of Earth and the same mass density is:
(1) v (2) 2v
(3) 3v (4) 4v Continue reading The escape velocity from the Earth’s surface is v ….
The maximum and minimum distances of a comet from the Sun are $1.6 \times 10^{12}$ m and $8.0 \times 10^{10} $ m respectively. If the speed of the comet at the nearest point is $6 \times 10^4 $ m/s, the speed at the farthest point is:
(A) $3.0 \times 10^3 $ m/s
(B) $1.5 \times 10^3 $ m/s
(C) $4.5 \times 10^3 $ m/s
(D) $6.0 \times 10^3 $ m/s Continue reading The maximum and minimum distances of a comet ….
The weight of any object on the Moon gets reduced to 1/6th of its value on the Earth. X can apply a maximum force of 300 N. The ratio of the maximum acceleration on the Earth to that on the Moon of a 6 kg object that X can throw is approximately:
A) 1 : 6
B) 31 : 36
C) 36 : 31
D) 6 : 1 Continue reading Acceleration on Earth Vs Moon
When a particle is thrown up vertically from the surface of the earth (radius R), we have v2-u2=2(-g)h (h << R) if the effects due to the atmosphere of the earth are neglected (symbols mean the usual things). However, if h << R condition is not applicable, prove that 
Continue reading $$v^2-u^2 \neq 2as$$
