question: Write a question you would see in a school textbook. OPTIONS:
- the force of gravity
- the force of friction
- the force of magnetism
- the force of the student's push
answer: A student sets a block at the top of a wooden ramp. The student pushes the block. As the block slides down the ramp, it slows down and then comes to a stop. What force causes the block to slow down?

question: Write a question you would see in a school textbook. OPTIONS:
- to overcome Earth's gravitational force
- to protect equipment from radiation
- to break through the sound barrier
- to avoid Earth's magnetic field
answer: Why do satellites and spacecraft launched from Earth need to reach a specific speed to escape Earth's surface?

question: Write a question you would see in a school textbook. OPTIONS:
- only its protons
- only its electrons
- both its protons and neutrons
- both its neutrons and electrons
answer:
A student needs to find the mass of an atom. The numbers of which atomic particles determines the mass of the atom?