Jerry walks into the gym for his first lesson and is amazed at Wanda's ability to do a round-off back handspring and wants to be able to do this gymnastic skill too. Prior to trying this skill, which safety consideration should he think about first? His chronological age
His friend's encouragement
His physical height
His tumbling experience

Imagine that someone pushes one marble toward a motionless marble. would there still be action-reaction forces involved in the collision? how might the marbles’ motions be changed? ?

The diagram shows a series of volcanic island and a hot spot determine the direction of movement of the tectonic plate that for the island

Global warming will produce rising sea levels partly due to melting ice caps but also due to the expansion of water as average ocean temperatures rise. to get some idea of the size of this effect, calculate the change in length of a column of water 1.00 km high for a temperature increase of 1.00ºc. note that this calculation is only approximate because ocean warming is not uniform with depth. (answer in ×10^{-3} −3 m)