If element X has 90 protons, how many electrons does it have?

If the volumes of the two rocks are equal the rock with the greater density has what

Does the density of aluminum ever change?

Enter expression 2cos^2 (ø) - 1

0.05 kg bullet is fired to the north from a 4.0 kg rifle that is initially at rest. The bullet leaves the rifle with a momentum of 20 Ns. Determine the total momentum of the bullet-and-rifle before the bullet is fired?

A 10 kg block slides on a frictionless surface at 10 m/s. It hits a rough patch 3 meters long with a coefficient of kinetic friction of 0.4. When it reenters the frictionless surface, how fast is it going?

What's the definition of: • cellular respiration • photosynthesis

What are the steps that are important to take for your safety during an earthquake? a. stay away from walls and windows c. stay away from electrical and gas lines b. get under a desk or table d. all of the above

You have an open air column of length 1.40 m in air at 24.2 °C. What is the frequency of the third harmonic?

Why do we use average force while solving momentum problems? How is net force related to the momentum of the object?

If you had a positive 8 score on the sit-an-reach test you