Science Questions

T/FAlthough antimatter is an interesting theoretical idea, there is no evidence that it actually exists.

Astronauts in a space shuttle can float while orbiting Earth. Why are these astronauts weightless?

Imagine you are walking along a forest path. Which of the following is not an action-reaction pair in this situation?

F is the force that is causing the object to accelerate. In the case of dropping objects from a height, the force that causes them to accelerate toward the Earth is gravity. If the acceleration of objects dropped from a height does not depend on the object’s mass (as shown by Galileo’s experiment), what does this imply about the force of gravity?

Suppose you read on the Web that a new planet has been found. Its average speed in its orbit is 33 kilometers per second (km/s). When it is closest to its star, it moves at 31 km/s, and when it is farthest from its star, it moves at 35 km/s. This story is in error because

If a planet is in equilibrium, the energy coming in ________ the energy going out.

If the energy leaving the planet is restricted, what happens to the amount of energy trapped on the planet?

Which of the following portions of the EM spectrum can be observed easily from the ground?

Which of the following values given for the Doppler shifts of astronomical bodies indicates that the object is approaching fastest (blueshifted)?

Rank the planets according to how well they retain their atmospheres from most successful to least successful

Besides adding adaptive optics to a telescope, what else can be done to reduce the effects of seeing?

Sort each of the five terrestrial bodies into the appropriate category based on the type of atmosphere it currently retains, if any.

Four transitions are shown in the image. Identify the transitions in order of increasing wavelength of the photon that each transition would emit.

Newton's third law says that for every force there is an equal reaction force in the opposite direction. What does this imply about the force of gravity associated with a person standing on the Earth?

You are shopping for telescopes online. You find two in your price range. One of these has an aperture of 20 cm, and one has an aperture of 30 cm. Which should you choose, and why?

According to the article, the reason the Moon cooled so quickly is because it is 1 percent of Earth's mass. Why is this statement problematic?

Imagine two objects moving away from you. Object A is faster than object B. You will observe that the light

If the Moon were 2 times closer to Earth than it is now, the gravitational force between Earth and the Moon would be

The main greenhouse gases in the atmospheres of the terrestrial planets are

Lava flows on the Moon and Mercury created large, smooth plains. We don't see similar features on Earth because