While skateboarding at 19 km/h, Alana throws a tennis ball at 11 km/h to her friend Oliver. If Alana is the reference frame, the speed of the tennis ball is km/h.

Why do windows have two panes of glass separated by a layer of air

Renewable resources are resources that can be replaced faster than they are used. Which of the following energy resources is renewable? A. solar energy B. natural gas C. uranium D. petroleum

What gives the flow of time

The video shows an animated billiards experiment in which a cue ball strikes a glued-in-place eight-ball. which of the following explains why the momentum of the eight-ball is conserved?

What is the term for the scientific study of the universe? oceanography astronomy geology meteorology

When a bat uses echolocation to determine the distance to an insect, it sends out a sound wave and waits to see how long the sound takes to echo back. Suppose now that a bat hears its echo 0.06 LaTeX: ss after it emitted the sound.

An exhausted bicyclist pedals somewhat erratically when exercising on a static bicycle. The angular velocity of the wheels follows the equation? (t) = at? bsin (ct) fort?0, where t represents time (measured in seconds), a = 0.500 rad/s2, b = 0.

This boy uses a force to lift a heavy rock. (He is carrying it.) What can the boy do if he wants to lift the same rock more quickly? A. use greater upward force B. use greater downward force C. decrease the force of gravity D.

The difference in electronegativity values between H and O is 1.4. What type of bond will these elements form?

True or false. when light passes from one medium to another the speed changes.