5. which event marks the end of both the Paleozoic era and the mesozoic era?

A. cenozoic

B. mesozoic

C. paleozoic

D. precambrian

Does calm water have a regular reflection or a diffuse reflection

Consider the magnetic field (B) of a wire with a constant current (I). A Magnetic Field sensor is placed at a radius (r).

Which of the following statements concerning the scientific method is true? Once a scientific law is formed, it cannot be changed.

The products of a chemical reaction can never have greater mass than the reactants true or false

What is another word for the sound barrier? A. destructive interference B. light speed C. Doppler effect D. speed of sound

Which of these forces could speed up a baseball? A) Applied and Frictional forces B) Applied and Gravitational forces C) Frictional and Gravitational forces

When you are travelling downhill on a roller coaster, you experience a light feeling in your stomach. why?

Sound waves transport: a. only matter b. only energy c. both matter and energy d. matter when passing through a medium and energy passing through vaccum

What's the number 9?

A car travels along a straight line at a constant speed of 60.0 mi/h for a distance d and then another distance d in the same direction at another constant speed. The average velocity for the entire trip is 30.0 mi/h.