Two tuning forks are played at the same time. One has a frequency of 490 Hz and the other is 488 Hz. How many beats per second are heard? 490 488 2 4

Two slits separated by 0.10 mm are illuminated with green light (l = 540 nm). calculate the distance (in cm) from the central bright-region to the fifth bright band if the screen is 1.0 m away.

What is the most important safety rule in cycling?

If the the United States imports $100 million of goods and exports $150 million, what does the United States have?

A measurement must include both a number and a (an)

If you do not have oil in your car's engine, the parts that rub together in the engine get very hot. What does the oil do? A. It decreases the force of gravity. B. It increases the force of gravity. C. It decreases the force of friction. D.

Which of these rocks are formed by volcanic activity? select the two correct answers. a. marble b. basalt c. limestone d. granite e. sandstone

Which source is most likely an authority on the subject? Dr. Vale, a pediatrician, discusses electrical circuitry on her home-improvement website. Jonah, an amateur cook, teaches his son how to make the best grilled cheese sandwiches.

What methods can be used to break down substances into elements

8. A gas is contained in a horizontal piston-cylinder apparatus at a pressure of 350 kPa and a volume of 0.02 m3. Determine the work done by the piston on the gas if the cylinder volume is increased to 0.15 m3 through heating.

A 75.0 kg person stands on a scale in an elevator. (a) What does the scale read (in N and in kg) when the elevator is at rest?