A train is moving along a track with constant speed v1 relative to the ground. A person on the train holds a ball of mass m and throws it toward the front of the train with a speed v2 relative to the train.

What percentage of the earth's water is available for use by living things?

Alaser tag arena sells two types of memberships. one package costs $325 for one year of membership with an unlimited number of visits. the second package has $125 enrollment fee, includes five free visits, and costs and additional $8 per visit after the first five. how many visits would a person need to use for each type of membership to cost the same amount over a one-year period?

Essay on sustainable development of soiciety