Lance threw a ball straight up into the air. The ball's
gravitational potential energy at its peak height was
0.4 joules, and its speed when it hit the ground was
4 meters per second. What was the mass of the ball?

Two friends at different locations want to communicate with each other by sending low energy signals. which of the following methods can they use to communicate? a) produce x-rays using colliding electrons and send them to radios, which capture sound b) send messages using infrared radiation, which travel in the form of waves c) send radio waves through intervening media like radio and television d) produce sound waves using microwaves from heated objects

Bohr's model could only explain the spectra of which type of atoms? single atoms with one electron single atoms with more than one electron bonded atoms with one electron bonded atoms with more than one electron

Particle model to predict what will happen if a sharp object creates a hole in the soccer ball