What is the definition for model system

Which is not a branch of natural science: biology, chemistry, physics, psychology?

Did sodium lose electr on or gain

Explain how a balloon can become positively charged when rubbed with a cloth

Technician A says that distilled or clean drinking water should be added to a battery when the electrolyte level is low. Technician B says that fresh electrolyte (solution of acid water) should be added. Which technician is correct? A.

Momentum is mass times.

A toy helicopter begins flying across a field with a speed of 3 m/s and an acceleration of 0.8 m/s2. How long does it take the helicopter to reach a speed of 7 m/s?

A 50.0 kg child stands at the rim of a merry-go-round of radius 1.50 m, rotating with an angular speed of 3.00 rad/s. (a) what is the child's centripetal acceleration? incorrect: your answer is incorrect.

Do all types of waves need a medium to travel through

What feature of the ocean basin is formed when old oceanic crust is forced under continental plates

Thermal energy from the Earth's core heats rock and creates magma. This hot magma then rises toward the Earth's surface, cools, and sinks back down toward the Earth's core. Which actions below occur during this process? (multiple answers) A.