Why aren't iron, cobalt and iron in the same group of elements?

Which is likely to produce the brightest spectra? A. Holographic gratings B. Reflection gratings on plastic C. Transmission gratings on glass D. Replica transmission gratings on plastic

Which of the following statements best describes earths mineral resources A. Valuable and renewable B. Valuable and non renewable C. Not valuable and renewable D. Not valuable and non renewable

What is easier to move a box from rest or to move it when it is already in motion

The intensity or brightness of light depends on

Which of the following best describes Biology A. an applied science B. a social science C. Not a Science D. A basic science

The first law of thermodynamics states that ΔE = Q - W. Is this also a statement of the principle of conservation of energy? Yes, the heat added and the change in internal energy of the gas equal the work done by the piston.

How can we calculate the density of a sustance that has irregular volume

A two stage rocket leaves its launch pad moving vertically with an average acceleration of 4 m/s2. at 10 s after launch the first stage of the rocket (now without fuel) is released.

A liquid filled sealed system has cylinders with movable pistons on each end. The face of one piston has an area of 5 cm². The other piston has an area of 500 cm² and is supporting a weight of 2 kN on it.

A turntable is spinning on a frictionless axle when a ball of putty is dropped onto it from above. The putty sticks to the turntable when it lands. Is angular momentum conserved for the turntable and putty (the system) during this process?