a train travels 99 kilometers in 3 hours, and then 80 kilometers in 5 hours. What is it's average speed?

Zain is standing on a bridge. He tosses a ball upwards, which rises, stops, and then falls all the way to the water (30 meters below Zain). Suppose that the speed at which Zain tosses the ball 1.50 m/s, and then answer the following two questions.

Electromagnetic waves differ from the other types of waves because they are

When work is done on an object, the object gains energy. true or false

You catch a volleyball (mass 0.270 kg) that is moving downward at 7.50 m/s. In stopping the ball, your hands and the volleyball descend together a distance of 0.150 m.

What causes the bright lines seen in the emission spectrum?

If you have a beam perfectly balanced on a fulcrum and put a weight at the very end of one side, is there a way to know where you should put a heavier object on the other end?

Most of the Earth's volcanoes occuWhen fossils or minerals form, certain unstable elements are sometimes locked into them.

a man is standing on the edge of a 20.0m high cliff. he throws a rock vertically with an initial velocity of 10.0m/s. how high does the rock go?

The slope of a velocity time graph over any interval of time gives the during that interval

if light travels in a vacuum at 3.00 x 10^8m/s and its frequency is 7.44 x 10^7 what is its wavelength