Explain the method of testing the speed of a shuttle.

Method of testing the speed of a shuttle: 1. The tester stands on the back boundary line and strikes the shuttle with a full underarm stroke. 2. The stroke is made from above the back boundary line and must be at an upward angle. 3. The shuttle must land on the opposite back boundary line and fall not less than 530 mm and not more than 990 mm short of the other back boundary line. 4. If the shuttle lands within this range, its speed is correct.