What kind of reaction occurs when potassium is placed in water? a. a single-displacement reaction c. a decomposition reaction b. a double-displacement reaction d. electrolysis

Which of the following can supply the energy for modern home heating systems? electricity biomass solar geothermal

A small rubber ball and a bowling ball are about to be dropped from the same height. Which has more gravitational potential energy?

What stores energy for a quick release in a cell?

What activates a convection current starting the flow of liquid

Which of the following statements is/are true? Check all that apply. A nonconservative force permits a two-way conversion between kinetic and potential energies.

A star has a mass of 1.36 x 1030 kg and is moving in a circular orbit about the center of its galaxy. the radius of the orbit is 2.1 x 104 light-years (1 light-year = 9.5 x 1015 m), and the angular speed of the star is 1.1 x 10-15 rad/s.

Floating in deep space, you find yourself at rest next to a small asteroid. You reach out and tap the asteroid with a hammer. What happens to you in this process?

You walk forward at 1.5 m/s for 8s. Your friend decides to walk faster and starts out at 2.0 m/s for the first 4 s. Then she slows down and walks forward at 1.0 m/s for the next 4s. Make a distance-time graph of your motion and your friend's motion.

If the coolant in a refrigerator was not compressed back into a liquid after it flowed through the refrigerator what would happen

A electric model train travels at 0.339 m/s around a circular track of radius 1.75 m. How many revolutions does it perform per second, i. e, what is the motion's frequency?