1. When you toss a ball upward, by how much does its upward speed decrease each second? 2. Joints are places where bones meet. Many of them, such as the ball-and-socket joints in your shoulders and...

1. When you toss a ball upward, by how much does its upward speed decrease each second?

2. Joints are places where bones meet. Many of them, such as the ball-and-socket joints in your shoulders and hips, are bathed with synovial fluid, a viscous substance resembling the white of an egg. Speculate about what the purpose of the synovial fluid might be.