In which situation is no work considered to be done by a force? a. when the angle between the force and displacement is 180° b. when the angle between the force and displacement is 90° c. when the angle between the force and displacement is 45° d. when the angle between the force and displacement is 0°

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.