Using standard formulae, derive an expression for the final speed of a falling object in terms of its change in height. Assume zero air resistance or other resistive forces.

Ek = (1/2)mv2

Ep = mg(dh)

Set these equal to each other, because of conservation of energy:

(1/2)mv2 = mg(dh)

Cancel the mass:

(1/2)v2 = g(dh)

v2 = 2g(dh)

v = (2g(dh))1/2

DL

Related Physics GCSE answers

All answers ▸

An Electric Kettle is used to boil water. After the water is boiled, the temperature of the water decreases by 22C. The mass of water in the kettle is 0.50 kg. The specific heat capacity of water is 4200 J/kg C. Calculate the energy transferred.


A car is travelling at 10m/s. It then accelerates at a constant rate.Find the time taken for the car to travel 1km if the car’s final velocity is then 22m/s .


Explain what is meant by “terminal velocity” with regards to falling objects.


A car travels 100 metres in 20 seconds. i) What is the cars speed? ii) How far would the car travel in 1 minute 40 seconds?