How could a rock be changed but still be classified as the same form of rock?

A 75.0-kg firefighter climbs a flight of stairs 28.0 m high. How much work does he do?

A suitcase is pulled 28 feet along a flat sidewalk with a constant upward force of 80 lb at an angle of 23degrees with the horizontal. Calculate the work done.

Which of the following is a personal decision that involves science A) It is immoral to cheat on your homework? B) what movie will I like the most this weekend? C) will an air purifier reduce the dust in my house?

Does heating a metal wire increase or decrease its electrical resistance? Why?

If a car traveled 50ml/h and a person walked 5km/h which one traveled the greatest distance?

If a car engine burns an equivalent of 20,000 joules of energy and attains a kinetic energy of 5,000 J, how much energy is dissipated in the form of heat?

If the speed of light in a vacuum is twice that of the speed of light in a given material, what is the index of refraction for that material?

In an electric motor, the rotating coil of wires wrapped around an iron core is a (n)

Which of the following best explains why the end of a spoon sticking out of a cup of hot water also gets hot? The hot water causes a chemical reaction to take place in the spoon.

Which of the following is an example of a research topic that is too broad? A. All about hip-hop music B. Hip-hop and the voice of outrage C. Rhyme and meter in hip-hop music D. Block parties and the origins of hip-hop