Atoms of element A decay to atoms of element B with a half-life of 20,000 years. If there are 10,000 atoms of A to begin with (and 0 atoms of B), how long will it take for there to be 2,500 atoms of A?

Two 4.0kg masses are 1.0m apart on a frictionless table. Each has 1.0μC of charge. Part A What is the magnitude of the electric force on one of the masses? What is the initial acceleration of each mass if they are released and allowed to move?

Compare and contrast bio-mass and hydroelectricity as sources of energy.

A man, holding a weight in each hand, stands at the center of a horizontal frictionless rotating turntable. The effect of the weights is to double the rotational inertia of the system.

Describe Why is it difficult for a human to travel long distance in space

Which of the following statements is NOT true? When a light wave encounter a boundary where they must bounce off of a surface with a larger index of refraction, the phase of the wave flips by pi A monochromatic light source is one that consists of

What type of energy is formed when chemical bonds are broken? A. Chemical energy B. Thermal energy C. Radiant energy D. Light energy

The liquid contained in batteries that conducts electric charge is called the: solution, electrolyte, suspension, colloid

Someone jumped from a high altitude at 31,000m above the earth. he freefalled for 4 min and 36 secs with top speed of 988 mph

What does the law of reflection mean?

Compared with the peak wavelength given off by the sun, what is the peak wavelength given off by a hotter star? A.) shorter in wavelength and higher in energy B.) shorter in wavelength and lower in energy C.