The hard external covering of some invertebrates is called a what

Is 'velocity'the displacement of an object during specific unit of time?

Juan is standing on the street. An ambulance moves toward him and then passes by. What best describes the pitch that Juan hears? The pitch remains constant as the ambulance moves toward and then away from Juan.

Why shouldn't we look at the sun directly? 100pts

Ocean waves are hitting a beach at a rate of 2.0 Hz. The distance between wave crests is 1.5 m. Calculate the speed of the waves.

Which statement is a characteristic of a convex lens? A. It absorbs most light. B. It is thickest at the edges. C. It bends light rays inward. D. It is always made of glass.

What happens if a hypothesis is not supported?

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?