- #1
RachelT
- 9
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Homework Statement
Using the formulae for potential energy and kinetic energy, find the speed that a tennis ball hits the ground when dropped from a height of 20m.
With reference to the principle of conservation of energy, explain why you could use these equations and what assumptions you have made.
Homework Equations
KE = 1/2mv^2
PE = mgh
The Attempt at a Solution
The first part I think I'm ok with. The tennis ball is dropped therefore no KE only PE.
PE = 9.8 x 20 = 196 Joules.
It is the second part that I don't really understand. What is it asking me? Can somebody maybe re-frase this part of the question. Thank you.