To score in the 85th percentile at age 15 in the President's Challenge, girls must A. complete the shuttle run in 9.0 seconds
B. run a mile in 8:08
C. complete 11 pull-ups
D. perform 57 curl-ups in 60 seconds

Awave is produced in a rope. the wave has a speed of 33 m/s and a frequency of 22 hz.

This is the substance(s) formed in a chemical reaction.

Engineers find a new metal that is stronger than steel but much lighter. this material is also significantly cheaper than what is currently used for most aircraft, available in large quantities, and easy to manufacture. the engineers are excited because this new material will lower the costs of buying and operating airplanes for companies. what is probably the best step for the engineers to make next?