Explain how machines can be useful if the output work is always less than the input work

What are disadvantages with friction?

Where do objects becomes weightless and why?

What will happen to thermal condictivity of a substance if its thickness is doubled? Also give reason.

Before You Begin: You may either copy and paste this document into a word processing program of your choice or print this page. To complete the chart below: Go back to the lesson on the historical models.

A radioactive isotope has a half-life of ten days. how much of a 100 gram sample will be left after 20 days

What is the mid-atlantic ridge? how many miles does it stretch?

A basketball player jumps straight up for a ball. To do this, he lowers his body 0.260 m and then accelerates through this distance by forcefully straightening his legs. This player leaves the floor with a vertical velocity sufficient to carry him 0.

Why does Mars have moons even when its mass is small?

During the forging process for a steel sword, the blacksmith places a hot iron blank into a cold bucket of water. Which of the following happens? A. The water molecules move faster. B. The steel molecules move faster. C.

If you are trying to balance a seesaw and you have a higher mass on the left, should the mass on the right be placed at a greater distance or lower distance to balance it? Why?