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Derive the mgh approximation for gravitational potential energy.

Newton's law of gravitation -> GPE = GMm/r - GMm/(r+h)GPE = GMm(1/r - 1/(r+h))GPE = GMm(h)/(r(r+h))r >> h -> GPE ~ (m)(GM/r^2)h = mgh

Answered by Inigo S. • PAT tutor

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How unified was Italy in the period 1871-1914?

By 1871 Italy had come into being as a legally unified country. Disparate states and kingdoms were brought together under one unified legislative and executive body. This question examines the extent to w...

Answered by • History tutor

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An object is let in free fall from a platform 20m high above Earth's surface. Describe the event in terms of energy and thus determine the speed of the object when it hits ground. Air resistance is negligible and gravitational acceleration is constant.

When the object is at rest on the platform it has no kinetic energy, but only potential energy. The potential energy is mgh where m is the mass of the object, g the gravitational acceleration and...

Answered by Cristina-Andreea A. • Physics tutor

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What are the similarities/differences between neuromuscular junctions and cholinergic synapses?

There are many similarities between these two structures, the main differences are: Neuromuscular junction (NMJ) is between a neurone and a muscle. A synapse is neurone-neurone.Neuromuscular junctions are...

Answered by • Biology tutor

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Analyse the level of economic efficiency achieved [short run] in a monopolistically competitive transport market (15 marks)

Start by defining the relevant market (e.g. monopolistic competition). This should follow along the lines of: ‘a market structure where many firms operate providing slightly differentiated goods and servi...

Answered by Mark A. • Economics tutor

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