Mechanical waves travel as disturbances in a physical medium how do electromagnetic waves travel

Electrons in excited hydrogen atoms are in the n = 3 energy level. How many different photon frequencies could be emitted as the atoms return to the ground state? (1) 1 (3) 3 (2) 2 (4) 4

About how long would it take a car driving at 17 m/s to travel 100 m? A. 4 s B. 5 s C. 6 s D. 7 s

In what distance will a car traveling with 100 kN stop if a force of - 200N is applied?

With what speed does the cart recoil if the projectile rises 2.1 m at its maximum height?

A diffusion couple composed of two silver - gold alloys is formed; these alloys have compositions of 98 wt% Ag-2 wt% Au and 95 wt% Ag - 5 wt% Au.

What happens when you shoot a bullet into the sky?

If you want to lift a 5-kg box to a height of 2 meters, how much work must be done? O A. 2J O B. 50 J O C. 98 J O D. 100

A diver initially moving horizontally with speed v dives dives offthe edge of a vertical cliff and lands in the water a distance dfrom the base of the cliff.

What is the Isotope notation for a Lithium atom?

Which best describes the direction of heat?