There are only about 118 known elements. How is it possible that all matter in the universe is made up of just over 100 elements?

A barbed-wire barrier erected by the East Germans between East and West Berlin that eventually was rebuilt of concrete

What is required for heat to be transferred by radiation?

Genetic therapy and engineering

A 0.25 kg steel ball is tied to the end of a string and then whirled in a vertical circle at a constant speed v. The length of the string is 0.62 m, and the tension in the string when the ball is at the top of the circle is 4.0 N. What is v

A mango fruit drops from the top of it's tree which is 40 m. How long does it takes to reach the ground

A swimmer jumps from a waterfall thats is 8.5 m high from the lake below. How fast must he run horizontally to dive 2.5m away from the base of the waterfall?

What happens (as far as energy goes) when a molecule of gas strikes the wall of a container?

The boom of a fire truck raises a fireman (and his equipment - total weight 280 lbf) 60 ft into the air to fight a building fire.

Two masses are separated by 1 m. suppose the masses are moved so they are 2 m apart how will the gravitational force change

Bob rubs a piece of fur on a hand rubber rod, giving the rod a negative charge. what happens?