Which of the following is an element?

a. o2

b. CaCl2

c. HPO4

d. CO2

(also i'm freshman in high school, idk why it's saying middle school)

Which involves reflection of light waves? A. A full moon shows sunlight bouncing off the moon's surface and traveling toward Earth. B. Ultraviolet waves of energy are taken in by sunburned skin ... C.

A carnival ride has a 2.0m radius and rotates once each. 90s. Find the centripetal acceleration

If do 50 J of Work in 20 seconds, what is my Power?

What is the net force acting on a 1-kg ball in free fall?

When the particles in a medium vibrate perpendicular to the direction the wave is traveling, this type of waves is called a: A. Transverse wave B. Longitudinal wave C. Surface wave D. Tidal wave

Which of the following do not involve a direction? Check all that apply. A. Time B. Velocity C. Distance D. Acceleration

What does deltaX mean in physics?

Which activity involves using fossil fuels directly or indirectly? 1) eating fresh fruit for a snack 2) cooking hot dogs on a campfire 3) using crayons to color 4) walking to school

Which of the following objects would have the most inertia? A. A sphere with a radius of 5 cm and a mass of 34 grams. B. A sphere with a radius of 4 cm and a mass of 15 grams. C. A sphere with a radius of 8 cm and a mass of 27 grams. D.

A boy slides a book across the floor using a force of five and over a distance of 2M what is the kinetic energy of the book after he slides at assume there is no friction