How is the energy of coal released

A particular spectral line from an observed object is measured to be at a wavelength of 400 nm. that same spectral line is found to have a wavelength of 800 nm when measured at rest in the lab. what is the radial velocity of the observed object?

A nylon guitar string vibrates in a standing wave pattern shown below. 2.7 m what is the wavelength of the wave? answer in units of m.

Formed when constructive and destructive interference occur at the same time in a wave

Why would elements found in the same group on the periodic table have similar reactivity's A. They have the same number of protons B. They have the same number of energy levels C. They have the same atomic mass D.

What are examples of newton's 3 law

The speedometer in your car reads 55 mi/h. This represents the what of the car

Since the moon has less mass then the earth what happens to objects on the moon A. They fall slower B. they fall faster C. they don't fall D. They fall at the same rate as they do on earth

An electrical motor spins at a constant 2035 rpm. if the armature radius is 5.862 cm, what is the acceleration of the edge of the rotor?

If a car engine burns an equivalent of 20,000 joules of energy and attains a kinetic energy of 5,000 J, how much energy is dissipated in the form of heat?

If the speed of light in a vacuum is twice that of the speed of light in a given material, what is the index of refraction for that material?