CONTACT FORCES The force applied by a magnet on an iron nail.
The force applied by a student on a door to open it.

NON-CONTACT FORCES
The force applied by an electromagnet on a wire.
The force applied by the planets on each other.

Which statement best explains why the table is incorrect?
A. Magnetic force is a force acting at a distance
B. The student applies a non-contact force on the door
C. Electromagnets use contact force
D. Gravitational force acts between planets only when they are in contact.

Asolution contains 225 g of sodium chloride, nacl, dissolved in enough water to make a 0.25 l of solution. what is the molarity of the solution?

Which fact represents evidence for the big bang theory?

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.