Which of the following is a definite indicator of a chemical change?

A.

The shape of a substance is changed.

B.

A new substance is formed.

C.

A substance is converted from a liquid to a gas.

D.

The change in a substance is reversible.

A runaway railroad car, with mass 4.50 * 105 kg, coasts across a level track at 3.80 m/s when it collides with a spring-loaded bumper at the end of the track. If the spring constant of the bumper is 3.

A Web of proteins in the cytoplasm is know as the

Combining which of the following substances with germanium will cause the germanium to emit free electrons? A. Bismuth B. Gallium C. Aluminum D. Indium

Which of the following is a reason for the start of the space race? Too many scientists were unemployed. Congress was very interested in outer space. The U. S. president was a science fiction fan.

You kick a ball with a speed of 18 m/s at an angle of 32 degrees. How far does the hall land?

How does the tilt of Earth's axis affect how the sun's rays strike Earth?

A stone is tied to s string and whirled around in a circle at constant speed. Is the string more likely to break when the circle is horizontal or when it is vertical? Account for your answer, assuming the constant speed is the same.

Two blocks, stacked one on top of the other, slide on a frictionless horizontal surface. The surface between the two blocks is rough, however, with a coefficient of static friction equal to 0.50. The top block has a mass of 2.

Process by which water vapor changes to a liquid Evaporation Condensation Convection radiation

Part A Find the energy U0 stored in the capacitor. Express your answer in terms of A, d, V, and ϵ0. Remember to enter ϵ0 as epsilon_0.