Explain why it is sometimes necessary for scientists to replace a scientific model?

The helium that fills a balloon is an example of which state of matter?

Explain why Mercury, Venus, and Mars are not likely to support life as we know it.

A solid ball has a radius of 2cm and a length of 7cm. It has a density of 3.1g/cm3 What is the mass of the cylinder?

A hockey puck is hit by a hockey player at the goalie. The puck is hit with a 1200 newton force. The stick made contact for 0.1 seconds. What impulse was given to the puck?

Two mountain bikers are rolling down a hill. They both have the same mass, but one is taller and has more air drag (friction, etc.) than the shorter one. Which will reach the bottom first?

What is the acceleration of all objects due to gravity? What does this mean?

Which is the correct formula for cellular respiration? a. 6 CO2 + 6 H2O + light energy → C6H12O6 + 6 O2 b. CO2 + H2O → C6H12O6 + O2 c. C6H12O6 + O2 → CO2 + H2O d. C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + ATP energy

A tree is standing in the middle of a meadow. As you watch, the wind begins to blow and the tree bends. Which statement best explains how you could tell that a net force was acting on the tree? OA) The tree had momentum.

Consider two cars, a 700kg Porsche and a 600kg Honda Civic. The Porsche is speeding along at 40 m/s (mph) and the Civic is going half the speed at 20 m/s.

Which statement about an electron in the 4d state is correct? A. The magnitude of its orbital angular momentum is 6√ℏ. B. The largest orbital angular momentum it could have in any given direction is 4ℏ. C.