CHAPTER 12. FORCE,MOMENTUM AND IMPULSE 12.4
(d) 16 R
- A satellite experiences a force F when at the surface of the Earth. What will be the force on the
satellite if it orbits at a height equal to the diameter of the Earth:
(a) F^1
(b)^12 F
(c)^13 F
(d)^19 F
- The weight of a rocklying on surface of the Moon is W. The radius ofthe Moon is R. On planet
Alpha, the same rock has weight 8W. If the radius of planet Alpha is halfthat of the Moon, and
the mass of the Moon isM, then the mass, in kg,of planet Alpha is:
(a) M 2
(b) M 4
(c) 2 M
(d) 4 M
- Consider the symbols of the two physical quantities g and G used in Physics.
(a) Name the physical quantities represented by g and G.
(b) Derive a formula forcalculating g near the Earth’s surfaceusing Newton’s Law of Universal
Gravitation. M and R represent the mass and radius of the Earth respectively.
- Two spheres of mass800g and 500g respectively are situated so thattheir centres are 200 cm
apart. Calculate the gravitational force between them.
- Two spheres of mass2 kg and 3 kg respectively are situated so that thegravitational force between
them is 2,5 x 10−^8 N. Calculate the distance between them.
- Two identical spheres are placed 10 cm apart. A force of 1,6675 x 10−^9 N exists between them.
Find the masses of the spheres.
- Halley’s comet, ofapproximate mass 1 x 1 015 kg was 1,3 x 10^8 km from the Earth, at itspoint
of closest approach during its last sighting in 1986.
(a) Name the force through which the Earth andthe comet interact.
(b) Is the magnitude ofthe force experienced by the comet the same, greater than or less than
the force experienced bythe Earth? Explain.
(c) Does the acceleration of the comet increase, decrease or remain the same as it moves
closer to the Earth? Explain.
(d) If the mass of the Earth is 6 x 10^24 kg, calculate the magnitude of the force exertedby the
Earth on Halley’s cometat its point of closest approach.
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(1.) 01wi (2.) 01wj (3.) 01wk (4.) 01wm (5.) 01wn (6.) 01wp
(7.) 01wq (8.) 01wr (9.) 01ws (10.) 01wt
