What creates a magnetic field

Whenever you watch a high-flying aircraft overhead, it seems that its sound comes from behind the craft rather than from where you see it. Why is this?

Which of these statements is not true about chemical reaction rates

What is the normal frequency for humans

To obtain the same resistance force, a greater force must be exerted in a machine of lower efficiency than in a machine of higher efficiency True False

A piston in a heat engine does 600 joules of work and 1,700 joules of heat are added to the system. Determine the change in internal energy and explain how this example demonstrates the conservation of energy.

a group of elements that stretch bend and conduct heat and electricity

A rectangular block has dimensions 2.9 cm x 3.5 cm x 10.0 cm. the mass of the block is 615.0 g. what is the volume and density of the block? (answer it with correct numbers of significant figures)

Which of the following are products of cellular respiration? Sunlight Oxygen ATP Water Carbon Dioxide

Do magnetic field lines ever start or end anywhere?

What effect do oceans have on the temperature of coastal areas? A. Ocean breezes warm the coastal land constantly. B. Ocean currents always cool a coastline. C. Ocean winds prevent extremes of temperature on coastal lands. D.