The strength of a rectangular beam varies jointly as its width and the square of its depth. if the strength of a beam 12 inches wide by 22 inches deep is 3400 pounds per square inch, what is the strength of a beam 9 inches wide and 18 inches deep?

When you drop a pebble from height a it reaches the ground with speed v if there is no air resistance. from what height should you drop it so it will reach the ground with three times the speed? (a) 9m (b) 3m (c) 6m (d) 18m

Using the work energy theorem. what is the velocity of a 850kg car after starting at rest when 13,000j of work is done to it.

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?