If a radioactivite material has 1 hour half-life, how much of a 1000 g sample will be left after 6 hours

What is the main reason the chemical energy of a fuel is never entirely converted to mechanical energy in an engine? A) Some of the energy is lost as heat. B) Some of the energy is converted to mass.

A 53-N force is needed to keep a 50.0-kg box sliding across a flat surface at a constant velocity. What is the coefficient of kinetic friction between the box and the floor?0.11 a) 0.10 b) 0.13 c) 0.09 d) 0.11

The electroscope is an apparatus used to detect electric charge. The electroscope consists of a plate, a support and a free to rotate needle all made of metal.

In a population of desert plants, the timing of their blooming varies greatly. Some bloom early in the morning, others at mid-day, and others after dark. What environmental pressure might be an advantage for those plants that bloom after dark?

Two bullets have masses of 3.1 g and 4.4 g, respectively. Each is fired with a speed of 42.0 m/s. a) What is the kinetic energy of the first bullet? Answer in units of Jb) What is the kinetic energy of the second bullet?

Which physical property of iron made it popular for use in weapons? 1. Magnetism 2. Luster 3. Malleability 4. Ductility

a 2 kg rock is dropped from the top of a 30 m High building calculate the ball at the time that it strikes the ground

Water, with a density of rho = 1145 kg/m 3, flows in a horizontal pipe. In one segment of the pipe, the flow speed is v 1 = 7.33 m/s. In a second segment, the flow speed is v 2 = 1.57 m/s.

What does the color of a star determine

Scientific cosmology Choose one: A. investigates the overall structure and history of the Universe. B. pertains to legends and verbal history about the beginnings of the Universe. C. proves the Big Bang theory. D.