How many neutronss are in an atom of oxygen with a mass number of 18?

Three particles are moving perpendicular to a uniform magnetic field and travel on circular paths (see the drawing). They have the same mass and speed. List the particles in order of their charge magnitude, largest to smallest.

Ilya and Anya each can run at a speed of 8.90mph and walk at a speed of 3.80mph. They set off together on a route of length 5.00miles. Anya walks half of the distance and runs the other half, while Ilya walks half of the time and runs the other half.

The mechanical advantage of a wheel and axle is the ratio of what?

Imagine that you are jumping rope, explains how these 3 types of energy would be present while doing so. (Chemical, Sound, Mechanical)

Why is it very important that only one variable be changed in a n experiment

What is the energy source that heats a contracting protostar?

What unit is kg divided by m/s^2

If the energy stored in the fully charged battery is used to lift the battery with 100-percent efficiency, what height is attained? Assume that the acceleration due to gravity is 9.8 m/s2m/s2 and is constant with height

How does the mass of an astronaut change when she travels from earth to the moon? how does her weight change?

If an object has a mass of 20 grams and a volume of 40 cm3, what is its density in g/cm3?