Yahoo Answers is shutting down on May 4th, 2021 (Eastern Time) and beginning April 20th, 2021 (Eastern Time) the Yahoo Answers website will be in read-only mode. There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.

? asked in 科學其他:科學 · 10 years ago


(I)An object is thrown up from the top of a building 50 m high,It rises to maximum height of 20 m above the roof.

(a)When does it land on the ground?

(b)At what velocity does it land?

(c)When is it 20m below the roof?

(II)An object is fired vertically up from the ground.Find its maximum height and the time of flight given that it loses 30%of its initial speed in 1.8s and is moving upward.

1 Answer

Still have questions? Get your answers by asking now.