How can weathering and erosion be a problem?

The a metal retainer that keeps the rolling elements evenly spaced. n a. seal n b. separator n c. bearing n d outer race

In which of the following is positive work done by a person on a suitcase

Ahot-air balloon is 11.0 m above the ground and rising at a speed of 7.00 m/s. a ball is thrown horizontally from the balloon basket at a speed of 9.00 m/s. ignore friction and air resistance and find the speed of the ball when it strikes the ground.