A 55.0 kg ice skater, initially at rest on a flat skating rink, requires a 188.0 N horizontal force to be set in motion. However, after the skater is in motion, a horizontal force of 167.0 N keeps her moving at a constant velocity. Find the coefficients of static and kinetic friction between the skates and the ice.

QUESTION:

How can inheritance of traits affect a crop’s ability to survive disease?

ANSWER:

The foundation of Mendelian genetics enabled plant breeders to cross plants with new precision, carefully manipulating the plant genome to produce new, improved varieties. These breeding techniques have been used to develop higher-yielding varieties, including plants resistant to pests or disease. These improved varieties have contributed to a dramatic explosion in agricultural output. In the past 50 years in the United States, farm productivity has increased two-and-a-half times, while farm acreage has declined 6 percent. One of the most spectacular successes was the development of hybrid corn in the 1930s, which quickly doubled corn yields.