Which of the following is a physical change? (1 point) A newspaper burns when placed in a fire.
An iron chair rusts when left outside.
A sample of water boils and releases gas.
A plant changes carbon dioxide and water into sugar.
Electricity is used to split water molecules into hyrdogen and oxygen

The passage that directs air to the lungs is called a. diaphragm. b. larynx. c. bronchi. d. pharynx.

Tall pacific coast redwood trees can reach heights of about 100 m. if air drag is negligibly small, how fast is a sequola cone moving when it reaches the ground f it dropped from the top of a 100 m tree?

Consider a uniformly charged ring in the xy plane, centered at the origin. the ring has radius a and positive charge qdistributed evenly along its circumference. a)what is the direction of the electric field at any point on the z axis? . b)what is the magnitude of the electric field along the positive z axis? use k in your answer, where k=14πϵ0. d)the ball will oscillate along the z axis between z=d and z=−d in simple harmonic motion. what will be the angular frequency ω of these oscillations? use the approximation d≪a to simplify your calculation; that is, assume that d2+a2≈a2. express your answer in terms of given charges, dimensions, and constants