Is space-time and concept of "now" an illusion?

People with normal vision cannot focus their eyes underwater if they aren't wearing a face mask or goggles and there is water in contact with their eyes. Explain why not.

Explain the statement "the lower down in the food chain we eat, the greater percentage of solar energy we put to use, and the more people Earth can support" in terms of trophic levels and pyramids of energy.

Which of the following is the best definition of gravity?

If Planet Y orbits the Sun but does not rotate on its axis at all, how long would a day be on Planet Y?

A boy of mass 60 kg and a girl of mass 40 kg are together and at rest on a frozen pond and push each other apart. The girl moves in a negative direction with a speed of 3 m/s. What must be the final velocity of the boy?

For a cars speedometer what is the calculated speed over an entire trip

How does gravity influence our annual calendar?

A 0.500 kg block is sitting on a horizontal, frictionless surface. The block is connected to a horizontal spring with a force constant of 124 N/m. The other end of the horizontal spring rests against a wall. When a 100.

The velocity of waves in a ripple tank of a particular depth of water is 20 centimeters per second, and standing waves are produced with nodes spaced 2.0 centimeters apart. what is the frequency of the wave generator?

If a wave is generated in a Slinky and the wave hits a wall, the reflected wave will be