Leaving Certificate – Numerical Worksheet on Gravity & Gravitational force & Universal Law of gravitation

Last updated on May 6th, 2021 at 01:42 pm

This post presents a Leaving Cert Physics Gravity worksheet with Numerical Problems & solutions. You can take it as Leaving Certificate Universal Law of gravitation worksheet as well. You can browse through our post on the derivation of the law of gravitation and the formula of the gravitational force if you want to brush up on the formula used here.

Solved numerical problems on gravitation for Leaving Cert

1) If the distance between 2 objects is doubled then how will the gravitational force between them change?

2) If the distance between 2 objects is halved then how will the gravitational force between them change?

3) If the masses of the 2 objects are doubled then how will the gravitational force between them change?

Solution 1)

Solution:
F1 = GMm/r²
F2 = GMm/(2r)²
= GMm/4r²
so F2/F1 = ¼ ,
so the final gravitational force will be ¼ th of the initial gravitational force

solutions: continued

Solution 2)

Solution:
F1 = GMm/r²
F2 = GMm/(r/2)²
=4 GMm/r²

so F2/F1 = 4/1
so the final gravitational force will be 4 times of the initial gravitational force

Solution 3)

Solution:

F1 = GMm/r²
F2 = (G2M2m)/(r)²
=4 GMm/r²
so F2/F1 = 4/1
so the final gravitational force will be 4 times of the initial gravitational force

Solved numerical worksheet on Newton’s universal law of gravitation

The questions here on Gravitational force and Newton’s Law of Gravitation are extracted from a bigger set of numerical problems and hence the sequence # of the problems is kept unchanged for better tracking and linking with the solution pages.

34) Calculate the force of gravitation between two objects of masses 50 kg and 120 kg respectively kept at a distance of 10 m from one another. (Gravitational constant, G = 6.7 × 10 ^-11 Nm^2/kg^2 )

Solution: click this link for solution Q34

35) What is the force of gravity on a body of mass 150 kg lying on the surface of the earth?
(Mass of earth = 6 × 10^24 kg; Radius of earth = 6.4 × 10^6 m; G = 6.7 × 10 ^-11 Nm^2/kg^2)

Solution: click this link for solution Q35

36) The mass of sun is 2 × 10^30 kg and the mass of earth is 6 × 10^24 kg. If the average distance between the sun and the earth be 1.5 × 10^8 km, calculate the force of gravitation between them.

Solution: click this link for solution Q36

Gravitational force problems physics | Leaving Cert

44)
(a) An object has a mass of 20 kg on earth.
What will be its (i) mass, and (ii) weight, on the moon ?(g on moon = 1.6 m/s^2).
(b) Calculate the acceleration due to gravity on the surface of a satellite having a mass of 7.4 × 10^22 kg and a radius of 1.74 × 10^6 m (G = 6.7 × 10 ^-11 Nm^2/kg^2).

Solution: click this link for solution Q44

45) The mass of a planet is 6 × 10^24 kg and its diameter is 12.8 × 10^3 km. If the value of the gravitational constant is 6.7 × 10 ^-11 Nm2/kg2, calculate the value of acceleration due to gravity on the surface of the planet.

Solution: click this link for solution Q45