Who was the first scientist to observe cells? a. Theodor Schwann c. Anton van Leeuwenhoek b. Robert Hooke d. Matthias Schleiden

What causes thunder? a. static electricity in the air b. the sudden heating of the air by a lightning bolt c. the movement of raindrops and hail within the cloud d. the formation of raindrops out of rapidly condensing water vapor?

A telescope with a 60 mm objective lens collects how many times as much light as does your eye's 6 mm pupil?

Why do the planets move in fixed orbits around the sun?

The three different states of matter are liquid, solid, and gas. A solid is something you can hold in your fingers, while a liquid is something you can hold in a cup. Gases are all around you, making up the air we all breathe.

How to show your work for 0.04% of 245

You inflate a balloons with helium the balloons feel stiff, which properties of a gas best explains this observation the particles are moving quickly and far apart the particles are closley packed and vibrate in place the particles slide past each

Question 10 2.5 pts Which example identifies a change in motion that produces acceleration? a speed skater moving at an increasing speed on a straight track a vehicle moving down a straight street at a steady speed a particle moving in a vacuum at

If a 2,300 kg car is accelerating at 16 m/s^2, what is the force it is producing?

A hollow sphere of negligible mass and radius R is completely filled with a liquid so that its density is rho. You now enlarge the sphere so its radius is 2R and completely fill it with the same liquid. What is the density of the enlarged sphere?

what is the average speed of a person who can run around the track 4 times in 5 minutes? the track is 400 meters long.