When opposite poles of two magnets are brought together, the poles

A. attract each other.

B. repel each other.

C. cancel each other.

D. cause a net force of zero

A force of 100 newtons is used to move an object a distance of 15 meters with a power of 25 watts. Find the work done and the time it takes to do the work.

An object is transported to three different planets in our solar system. Which of the following is true about that object?

Which statements below describe the changes that molecules undergo when heat is applied to a single phase? (Select all that apply.) a. The heat energy causes an increase in the bond vibrations within the molecule. b.

A car's horn has a frequency of 1000 Hz. An observer hears the horn at a pitch of 1.10 kHz. If the speed of sound in air is 345 m/s, the speed that the car was travelling, relative to the observer, is ___ m/s.

The force of friction on an object is dependent on two things. what are they?

Which of the following is an example of heat transfer through radiation? A. A pot of soup warming on a hot burner. B. A crayon melting on a hot sidewalk. C. Beach sand getting warmed by the sun. D. An egg getting cooked in a pot of boiling water.

Which of the following best describes each particle? A. Protons are negative, neutrons are neutral, and electrons are positive. B. Protons are neutral, neutrons are positive, and electrons are negative. C.

During World War II, both the Allied and Axis powers used propaganda to A. weaken public support for the war. B. downplay public opinion. C. manipulate the public through the use of humor. D. shape public support of the war

What type of simple machine is a hand drill? A) pulley B) wedge C) ramp D) screw

Calculate the wavelength and frequency of the radiation emitted by the electronic transition from the 10th to the 9th excited state of hydrogen.