What is the key difference between mechanical and electromagnetic waves

What elements are stars mostly made of? How do we know this?

Assuming the same percent uncertainty and the same measurement device, what is the uncertainty in a blood pressure measurement of 71 mm Hg?

About how far does the S wave travel through Earth in 13 minutes? 2,000 km 4,000 km 6,000 km 8,000 km

What type of rock would you expect to form from the material found along a beach?

A girl is bouncing on a trampoline where is her gravitational potential energy a maximum and where is her kinetic energy maximum

The gravity of mercury is 3.7 n/kg. Find the mass of an astronaut who weights 241 Newton's on mercury

Why does oxygen have a lower ionization energy than nitrogen?

Traditional Indonesian music uses an ensemble called a gamelan that is based on tuned percussion instruments somewhat like gongs. In Bali, the gongs are often grouped in pairs that are slightly out of tune with each other.

An instrument used to detect a static electric charge is called an ammeter. a. true b. false

A heat engine has a cold reservoir of 250°C and a hot reservoir of 715°C. What is the efficienvy of the engine?