Why do scientists believe that dark matter exists even though it cannot be seen?

A ray of light is incident on an unknown transparent substance from of incidence is 40°, and the angle of refraction is 22° (a) Explain why these measurements indicate that a change in speed must be happening as the light changes medium.

Describe the shape of liquid water as it is poured into a glass. A. The shape stays the same as it was before it was poured B. The shape changes to fit the glass and then stays the same. C.

An object becomes charged when the atoms in the object gain or lose A protons B neutrons C electrons D all of the above

If a particle's position is given by x=4-12t+3t^2, where t is in seconds and x is in meters, what is its velocity at t=1 second?

A roller coaster at an amusement park girls from the top of a tall hill to the bottom during this time of the roller coaster

Name the three strata of study within the study of kinesiology define each and provide examples

Which of the following describes the products of a chemical reaction? A. The original materials B. The chemicals on the right side of a chemical equation C. The chemicals on the left side of a chemical equation D. The substances that are changed

What does it mean when we say an atom has decayed?

The first excited state of a particular atom in a gas is 5.2 eV above the ground state. A moving electron collides with one of these atoms, and excites the atom to its first excited state.

How do your teeth work as a wedge?