Gravitational potential energy

Question 1

Recall, derive and use the equation for the change in GPE in a uniform field:

Answer 1

• Δ𝑈G = 𝑚𝑔Δh

Question 2

Appreciate the limits of this equation

Answer 2

• g is assumed to be constant - g varies with Δh (g = g/r^2)
• 𝑚𝑔Δh cannot be used if Δh is comparable to the radius of the earth

Question 3

Appreciate the difficulty in defining absolute GPE

Answer 3

• We are interested in energy transformations therefore absolute GPE is often useful to us
• However, the problem is where is zero height! This does not matter as we just need Δh: provided g is constant

Question 4

Apply the principle of conservation of energy to problems involving the exchange of GPE, ESE and KE

Answer 4

See notes page