Physics

Give two examples of the techniques used by geologists to obtain values of the strength of the local gravitational field of the Earth?

Reply 1

Gagaha

The markscheme was useless for this question any help will be appreciated

Reply 2

ThirstyMan

Gravimeters measure the Earth's pull on a suspended mass and are precision instruments used on the land. You can also measure mean sea level as this will rise in areas of strong gravitational field strength and vice versa.

Reply 3

Gagaha

Original post by ThirstyMan

Thanks for the help but I have to answer it using A level content

Reply 4

ThirstyMan

Gravimeters use Newtons Law of Gravitation (Gm1m2/r^2) to determine the deflection of a suspended mass from the vertical and sea level uses ideas of density of the Earth and flotation (which is definitely A level) to determine the level of the sea that the land masses are floating in. Flotation problems always involve g as part of the density calculation.

Reply 5

ThirstyMan

PS I'm a Head of Physics and I mark A Level Papers for 3 UK exam boards and have done for the last 35 years, as a result I can pretty easily guess what is required in Physics content at this level. Don't worry, they are both good examples but you'll need to do a bit of research on both to firm it up but for 2 marks what I've already written will be enough.