What to do during study hall when you have no homework?

Which term describes the number of waves that pass a given point in a given time? crest frequency trough wavelength

How can you keep track of variables in a science experiment?

Identify the type of energy used in each action. the flexing of an arm muscle: a signal transduction process by a neuron: a ball at the top of a hill: 1. electrical energy 2. mechanical energy 3. gravitational potential energy