When a machine does work, a trade-off occurs. Which of the following best exemplifies this trade-off? A. A pulley changes the direction of your force, but requires a greater input force.

B. A lever increases output force and the distance the load moves.

C. A wheel and axle increases output force and the distance the load moves.

D. A ramp allows you to decrease force, but requires a greater distance.

1. list three scientific reasons cockroaches may fly.

Ageochemist examines a piece of metal that he found in the soil. he performs tests to identify the metal from its density, electrical conductivity, and melting point. which statement best describes his investigation? a. he is determining physical properties that are sufficient to identify the metal.b. he is determining chemical properties that are sufficient to identify the metal.c. he is determining physical properties that are insufficient to identify the metal.d. he is determining chemical properties that are insufficient to identify the metal.

What element has similar physical and chemical properties as boron.