Why is it better to build and test a prototype of a product than to pruduce tens of thousands of the product and then test it?

What is the density in g/ml of 25.00 milliliter of a 4.54% aqueous salt solution of mass 27.856 grams?

Sound waves can't travel through A. an elastic material. B. a liquid. C. a solid. D. a vacuum.

If an airplane flies at 364 km/h, how long will it take to get from New York to Washington DC (288 km) ? (If needed, round to the nearest thousandths and answer with unit 'h' for hours.)

Tara goes on a camel safari in Africa. She travels 5 km north, then 3 km east and then 1 km north again. What distance did she cover? What was her displacement?

What kind of uranium is used in atomic bombs? What are the proton and neutron numbers in the atoms?

The force of gravity acts upon meteors from the rocky asteroid belt between mars and Jupiter. Where is the force of gravity most likely to pull these meteors

Sally turns on her cellular telephone to speak to her friend who is located thousands of miles away. Which of the following best describes how such a telephone is able to transmit and receive information? A.

Calculate the gravitational potential energy relative to the ground when an 82 kg person climbs to the top of a 2.0 m stepladder.

A rock is thrown from a cliff and hits the ground five seconds later at a distance of 50 m from the cliff how high was a cliff

A 15.0 m long plane is inclined at 30.0 degrees. If the coefficient of friction is 0.426, what force is required to move a 40.0 kg mass from rest at the bottom on the plane to the top of the plane with a final velocity of 8.00 m/s?