Quadratic word problems, and choosing a method

Answer Key - Grade 9 Math Worksheet - Challenge Me

Circle the best answer, or write your answer on the line.

1. 1.

   Esme tosses a striped play ball up at 56 feet per second from the ground: h = -16t² + 56t. When is it 40 feet high for the first time, in seconds?

   1
2. 2.

   Jun kicks a soccer ball up at 64 feet per second: h = -16t² + 64t. When is it 48 feet high for the second time, in seconds?

   3
3. 3.

   Kira launches a toy foam rocket at 80 feet per second: h = -16t² + 80t. When is it 64 feet high for the first time, in seconds?

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4. 4.

   Luz tosses a basketball up at 72 feet per second: h = -16t² + 72t. When is it 56 feet high for the second time, in seconds?

   3.5
5. 5.

   Milo frames an 8 by 6 inch photo with an even border x inches wide. The framed area is 120 square inches. How wide is x?

   2
6. 6.

   Noah mounts a 10 by 8 inch drawing with an even border x inches wide. The total area is 224 square inches. How wide is x?

   3
7. 7.

   Pia's garden is 10 by 6 meters, with a path x meters wide all around. Garden and path cover 96 square meters. How wide is x?

   1
8. 8.

   In a science video Ari watches, a pebble drops from a 45 m bridge into a river: h = -4.9t² + 45. To the nearest tenth, after how many seconds does it land?

   3
9. 9.

   Bo times a water balloon a teacher drops from a 30 m tower onto grass: h = -4.9t² + 30. To the nearest tenth, after how many seconds does it land?

   2.5
10. 10.

    For an egg-drop project, Esme times a padded box a teacher drops from a 12 m balcony: h = -4.9t² + 12. To the nearest tenth, after how many seconds does it land?

    1.6