If a star contains a certain element, it can be determined by studying the star's

A. emission spectrum

B. corona

C. sunspot activity

D. main sequence

A 0.10 kg piece of copper at an initial temperature of 95°c is dropped into 0.20 kg of water contained in a 0.28 kg aluminum calorimeter. the water and calorimeter are initially at 15°c.

Which of the following describes a magnet that only has a field when a current is present? permanent magnet magnetic domain electromagnet magnetic pole

The yearly rainfall in the rainforest is between 50 - 260 inches? id weather or climate

A business letter style that shows all text aligned to the left side of the page is called a. full block. b. left block. c. justified block. d. modified block.

Which element is less reactive, an element who's atoms have seven valence electrons or an Element whose atoms have eight valence electrons? Explain.

An object has an acceleration of 24 m/s/s. How long would it take the stationary object to reach a velocity of 6.8 m/s?

What is normal distribution in statistics?

Which of the following water samples would be considered acidic

A linearly-polarized electromagnetic (EM) wave has an electric field with amplitude 1000 V/m. You hold a a linear polarizer in front of it and rotate the polarizer so that all of the EM wave is blocked. You then rotate the polarizer 30 degree.

Let y'=4 x. find all values of r such that y = rx^{2} satisfies the differential equation. if there is more than one correct answer, enter your answers as a comma separated list.