A boy drops a 0.10 kg stone down a 150 m well and listens for the echo. The air temperature is 20°C. How long after the stone is dropped will the boy hear the echo? The speed of sound through air at 20°C is v = 343 m/s.

Which tool converts sunlight into electricity? A. photovoltaic cell B. turbine C. battery D. copper tubing

The index of refraction for red light in a certain liquid is 1.303; the index of refraction for violet light in the same liquid is 1.326.

Measurement used for forced

Use the drop-down menus to explain how noise cancellation works. Waves with similar are created to interfere with unwanted sound waves. The wave overlap with the troughs of the other wave, causing the two waves to cancel out each other. of one

Which one of the following bodies has only potential energy? a. A ball rolling downhill b. A cat sitting on the fence c. A dog running after a car d. A stone falling from a cliff

Diane swim 5 kilometers against the current in the same amout of time it took her to swim 15 kilometers with the current. The rate of the current was 2 kilometers per hour. How fast would diane swim if there were no current?

A man paddles a canoe in a long, straight section of a river. The canoe moves downstream with constant speed 5 m/s relative to the water. The river has a steady current of 1 m/s relative to the bank. The man's hat falls into the river.

In an atom, almost all of the mass is concentrated in a tiny nucleus because

A truck travels down the highway at a speed of 110 km/hr. How long does the trip last if the truck covered 2200km?

Could tests be performed to support the clamim?