Test Question #9 Answers

Question: Close to the surface of the moon, the time a dropped object takes to fall to the surface can be calculated using the formula t= the square root of h/0.81. The time, t, is in seconds and the height, h, is in metres. If an object is dropped from a height of 250 m, how long does it take to reach the surface of the moon? Express your answer to the nearest tenth of a second. 

Textbook Pg. 81 #31

Question: The area of a triangle can be determined using Heron's formula, which requires the side lengths of a triangle. Heron's formula is 

In the formula A is the area; a, b, and c are the side lengths; and s is half the perimeter or a+b+c/2. Determine the area of each triangle with the following side lengths. Express each area to the nearest tenth of a square centimetre. 

a) 15 cm, 12 cm, 10 cmb) 9.3 cm, 11.4 cm, 7.5 cm

The area of the triangle is 59.8 square cm.

b) 9.3 cm, 11.4 cm, 7.5 cm

The area of the triangle is 34.7 square cm.