For what purpose is a screen name used?

if it takes 3.5 hours for the hogwarts express moving at a speed of 120 mi/hr to make it from platform 9 and 3/4 to hogwarts how far apart are they?

Does the mass of an object ever change ?

Satellite A revolves around Earth 5 times a day. What is the radius of its orbit, measured from Earth's center? Assume that Earth generates the only significant gravitation attraction on the satellite. Note: The mass of Earth is 5.

if you use the compound pulley, you will need to pull twice the distance but with less force. the force you need is equal to one half the weight of the box plus 25 N. what is the force needed?

Which of the following statements is true? A. Matter requires energy to move and change. B. Energy cannot change from one type to another. C. Energy must remain where it is created. D. It is not possible to store energy for later use.

Imagine you are holding an apple. Does this apple have energy? how do you know?

Explain how inertia and the shape of a loop counteract the force of gravity to keep riders from falling out when a roller coaster goes through a loop traveling upside down

Which is not a characteristic of an ideal fluid? A. high viscosity B. laminar flow C. constant density D. constant pressure

What type of weather system brings calm, clear weather?

What is one reason supporting genetic modifications to food