a packing crate with mass 80.0 kg is at rest on a horizontal, frictionless surface. at t = 0 a net horizontal force in the +x-direction is applied to the crate. the force has a constant value of 80.0 n for 12.0 s and then decreases linearly with time so it becomes zero after an additional 6.00 s.

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?

This graph represents four ecosystems. each ecosystem has a different number of species, adding to its biodiversity. different colors represent different species. which statements correctly summarize the data depicted by the graph? 1. ecosystem d has more biodiversity than ecosystem c. 2. ecosystem b has more biodiversity than all the other ecosystems. 3. ecosystem a has more biodiversity than ecosystem b but less biodiversity than ecosystem c. 4. ecosystem b has more biodiversity than ecosystems c and d but less biodiversity than ecosystem a. 5. ecosystem a has more biodiversity than ecosystem c but less biodiversity than ecosystem b.

Need will give 100 ! in no less than one hundred fifty words, explain why it is important for engineers to sketch designs and use them to clarify their designs to other people, giving at least three reasons.