What is needed to create change in a system?

Which of the following effects could not be observed for sound waves in air? Choose the correct answer: Interference Refraction Polarization Diffraction

Assume that you have a battery of emf e m f and three identical lightbulbs, each having constant resistance R. (a) What is the total power from the battery if the bulbs are connected in series? (Use the following as necessary: ℰ for e m f and R.

13/78 what is the simplest form for

A 1500 W radiant heater is constructed to operate at 115 V. (a) What will be the current in the heater? (b) What is the resistance of the heating coil? (c) How many kilocalories are generated in one hour by the heater? (1 Calorie = 4.18 J)

Which statements accurately describe the Doppler effect? Check all that apply. It is used to learn about the behavior of the universe. It was used by Hubble to measure velocities of galaxies. It indicates galaxy motion through light wavelengths.

A weather balloon is inflated to a volume of 2.2 x 10^3 L with 374 g of helium. What is the density of helium in grams per liter?

What is the result of a mutation during replication A: the strands are different B: the strands are identical c: the strands are broken D: the strands are continuous

What is ___ heating of a liquid__ gas to liquid

A gate in an irrigation canal is constructed in the form of a trapezoid 2 m wide at the bottom, 38 m wide at the top, and 2 m high. It is placed vertically in the canal so that the water just covers the gate.

A machine with a mechanical advantage of 10 is used to produce an output force of 250 newtons. What input force is applied to this machine