What is required for a sound wave to be reflected?

Rozważ, dlaczego telewizyjne satelity stacjonarne krążą nad równikiem. Zastanów się, czy można byłoby umieścić satelitę geostacjonarnego tak, aby jego orbita znajdowała się cały czas nad równoleżnikiem, np. przebiegającym przez Warszawę.

Lars, of mass 66.1 kg, can do work for about 2.00 min at the rate of 1.00 hp (746 W). How long will it take him to climb three flights of stairs, a vertical height of 15.0 m? Express your answer in seconds.

Lasers can be used in in place of a knife.

Is it normal to have 3 feet when you wake up?

A hammer is accidentally dropped from a scaffold where a crew is working. It takes the hammer 2.5 s to hit the ground. How high is the scaffold?

Based on the video, which venus phase would be impossible to see (from earth) of venus orbited earth as described in ptolemy's earth-centered model

Darrel noticed that his finger felt warmer in the ice water then did his left finger which of the following does the experiment show

Why is coal costly to produce? 1. coal is found deep underground. 2. Coal is expensive to make 3. Coal is only found in certain places on earth. 4. Coal is difficult to make in the lab.

Karen has a mass of 51.9 kg as she rides the up escalator at Woodley Park Station of the Washington D. C. Metro. Karen rode a distance of 63.1 m, the longest escalator in the free world. The acceleration of gravity is 9.8 m/s 2.

What is the current in a 160V circuit if the resistance is 2Ω?